Round the Horn or through Magellan - An extreme case of voyage planning

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PUBLISHED BY THE NETHERLANDS MARITIME INSTITUTE

ROUND THE HORN

OR THROUGHMAGELL4N,

An Extreme Case of Voyage Planning

Report Number R 109

17 MEl 1979

PiOject Number: SNAV 089

This report was prepared by:

C. Glansdorp, M..Sc.,P.Ri.N.

G H Goldsteen, B.Sc.

P. A. Kluytenaar

-.

ROUND THE HORN

OR THROUGH MAGELLAN

An Extreme Case of VOyage Planning

TABLE OF CONTENTS

Page

ABSTRACT i

INTRODUCTION . . ... . . .. iii

CONCLUSIONS AND RECOMMENDATIONS v

VOYAGE PLANNING . . . _. f

...

I I 1 Terms of Reference - . - 1 .1.2 GeneraiPhilosophy ... . . ...

.. .

.

...

. . 3

VOYAGE ENVIRONNT .

8 2.1

General ...

. . . .. .

...

8 2.2 I1éteorological Data a 8 2.3 Oceanographic Data . a . . .. .. . . . a 9 2.4 Geographic Data

...

.

...

1!

POSITION FIXING IN MAGELLAN STRAIT 15

SPECIFIC VESSEL CHARACTERISTICS 16

4.1 Theoretically Required Pathwi4th 16

4.2 Determination of Distance to New Course. . _.

.. . 16

5 COMPARISON OF ROUTE ALTERNATIVES 19

6.. TIME SCHEDULES OF THEPASSAGE THROUGH MAGELLAN STRAIT 22

THE AREAS OF CONSTRAINT AND THEIR NAVIGATION

MANPOWER REQUIREMENTS

EPILOGUE .

. . 23

24

TABLE OF bNTETS (contiiued)

APPENDICES

1. VOYAGE PLANNING

1.1 Description of the Route through Magellan Strait 1.2 Influence of Tide on Available Pathwidth

1.3 Descriptio of the ROute round Cape Horn

2 VOYAGE ENVIRONMENT

2.2 Meteorological Data

2.3 Oceanographic Data

2.4 Geographic Data

POSITION 'IXING IN MAGELLAN STRArr 3.1 Methods Employed

3.2 Accuacies at Specific Position 1n Magellan Strait

SPECIFIC VESSEL CHARACTERISTICS

4.1 theoetically Required Pathwidth.

4.2 Determination of Distance to New Course

CONPARISON OF ROUTE ALTERNATIVES

5.1 -The Inside Route Voyage Duration

5.2 Diffrence in Route Lengths

5.3 TimeLoss Rounding Cape. Horn

5.4 Conclusions

TIE SCIED1JLES OF THE PASSAGE THROUGH MAGELLAN STRAIT

THE AREAS OF CONSTRAINT ANI) THEIR NAVIGATION

7. 1 The Passage through Pri-mera Angostura and past Bano Trit6n

7..2 The assage from abreast o Pta. Pasaj.a to Isia Beware

7.3 Rquirements of Ship-basedPlanning

7 4 Worked Example of the Passage of Bajo Satflite and the 10 Fathom Patch

MANPOWER REQUIREMENTS WHEN PASSING THROUGH MAGELLAN. STRAIT LIST OF REFERENCES

1.1 1.2 1.3 1.4 1.5 2.1 2.2 2.3 2.5 2.6 3.1 4.1 4.2 4.3 4.4 4o5 4 ..6 4.7 4.8 4.9 4.10

TABLE OF CONTENTS (continued)

EXHIBITS

Block Diagram of Voyage Planning

Required Skill versus Time during a Voyage Pilot chart of the North Atlantic (Area ).

Pilot Chart of the South Atlantic (Area 50)

Variations in the Voyage Duration Base4 on a Ship Speed

of 15 Knots

Track of ss TULA at the Entrance .df EstrechO de Magillanes

Position of Grounding of ss METtJLA Daily Predictions fOr Puerto MOfltt

Daily Predictions for Bãha Santiago and Baha Felipe

Projected 'id'El CUrVe of 10 FthOm Patth, Januay 19th, 1975 Projected Tidal CurVe of 10 Fathom Patch, Jaivary 1st, 1975 Available Pathwidth and Depth along Magellan Strait

Extreme Limits of Icebergs

Mean Northerly limit of Icébetgs

Ship Draughts and Survey Danger Line Climatic Table - Grupo EvangelIstas Climatic Table .- Pta. Arenas

Climatic Table - Pta. Dungeness Parallel Index 'tedhnique

Increase of Required Pathwidth. Due to Crosswind/Current Ratio Available Pathwidth/Theoretically Requfred Pathwidthl Current Côntant: Drift Angle

Track during a Course Change Manoeuvre Distance tO New Course

Headitig- versus Time during aCourse Change Manoeuvre

Rudder Angle versus Time during a Course Change Manoeuvre

Schematized RUdder Angle foi

Calculation--Rate of Turn versus Time during a Course Change ;noeuvre:

Deviation of-f

TABLE OF CONTENTS (cOntinued)

4.11 Course Deviation at Cheek Time

4.12 Distance to New Course

4.13 Total Time for Completion of Course Change

4.14 Time at which Swing should be Checked

15 Course DeviatiOn at Check Time

4.16 Distance to NE COurse

4.17 Total Time for Completion of Course Change

4.18 Of f-Track Deviation

4.19 Results of Zigzag Tests.- ss METULA

4.20 Results of Zigzag Tests - ss NETULA

4.2.1 Results: of Spiral ests - ss T1.A

5.1 Average:Wind Distribution for Area 2 and Area.50

5.2 Time Los for. Different Wave Height

5.3 Relation between Median Wave. Period and Significant

Wave Height - Area' 2 and Area 50 5.4 Speed Loss versus Wave Height

5.5 Time Loss Distribution

5.6 Direction, Constariy and Ayerage Speed of Predominant

Current in Winter (July.). . . .

5.7 Pilot. Chart of the NorthAtlantic (Area. 2)'.- Decémbér

5.8 Pilot Chart of the NOrth Atlantic (Area. 2).- January

5.9 Pilot Chart of the North Atlantic: (Afea 2) .ebruary

10 . Pilot. Chart. of the South .Atl'ritjc (Area '50.) Winter.

5.11 "PilOt. Chart: of the. South Atlantic (Area 50) -' Spring'

5. 12 Pilot Chart of the South Atlant.i "(Area '50)

Sier

5.13. Pilot Chart of the, Sout1 Atlantic: (Area 50) Autumn'

1 Tidal Stréa. Rates accordirg to..BA and Chilean Cha.rt

6.2 Tidal S,reäm.Rate's according .to the Pilot

6.3 Tidal InforiatiOtz .'acco'ding to .ChiI'ear. Tide Tables, 1975

6.4': Daily Prediction.s, Standard Pors ' .

6.5 Daily Predictions, Secondary Ports .. .. ."

6.7 Times of Sunset, Sunrise and Civil Twilight during 1974

6.8 Sche4ule of Passage during Spring-Tides, Januaty 1, 1975

6.9 Schedule of Passage during Neap-Tides, Jafluary 19,. 1975

7. 1 Worked Example of Passage of Bajo Satlite and 10 Fathom Patch

7.2 Worked Example of Passage through Paso Tortuos.o

8.1 Examples Of Duty Division

Area Map

-1-ABSTRACT

This report discusses the planning of a voyage by a VLCC through

relatively unknown waters. It points out the navigation and

manoeuvring requirements in as far as they differ from routine practice or are considered to be unfamiliar to the average navigator and owner's fleet management department.

A detailed comparison is made of the route through Magellan Strait (Estrecho de Magallanes) and the alternative route

round Cape Horn (Cabo de Hornos). Upon completion of the desk

planning for these two voyages, it became clear that the nature of the route through Magellan Strait requires that the voyage be planned in the greatest detail, both by the owner's fleet management and the master of the ship, to ensure a safe passage. To be certain whether or not a passage is "safe" one needs to have on board an elaboration of the manoeuvring characteristics, obtained from sea trials, which can be used in predicting the

ship's track during course changes. Unfortunately this

inform-ation is usually not available on board. Also in some sections

of the Strait the accuracy with which a ship can be positioned might be insufficient to ensure that it is within its channel. At present only visual bearings and radar observations can be

used.

There are not enough navigation aids to assist the helmsman in

steering (accurately).

A large number of radar beacons (RACONS) should be installed. Charts are either unreliable or not sufficiently detailed.

From the meteorological point of view the route round Cape Horn

is not as bad as is generally believed. There is, however, not

conditions during the year and hence the. associated wave heights, direction and period.

This route certainly seems to be a feasible alternative to the Strait passage, which in the case Of such a large ship demands

from its officers constant ãt:téntion and precision over a

prolonged period of time. Besides this, they are: continuously

eposed to nterous submerged hazards, both charted and uncharted, tidal currents of up to 8 knots, the dangers of little searoom and general uncertainty about ay details.

This report was Tprimarily intended as an examp] of the extremely

detailed voyage planning which should be dOne by the owner's fleet.management and not as a source of ififOratiôn onthe

Cape Horn and Magell4n Strait area.

However, the information given and the recOendations made in this report have become more important now that independent

tanker owners have proposed sending tankers, coming from Val4ez,

Alaska and carrying crude oil to the eastern regions of the USA, roimd.Cape Horn or through Magellan Strait instead of through

INTRODUCTION

This report was commissioned by the Directorate of Shipping to

the Netherlands Maritime Institute a a. follow-up tO the results

of the investigation by thE Admiralty Court of the Netherlands

(Raad voor de Scheepvaart) in connection with the grounding of

the VLCC TULA on 9 August, 1974 and the subsequent analysis of this grounding by Captain A. Wepster, Head of the Navigation

Research Centre, NMI. An abstract of the. relevant facts of the

voyage is contained in the Epilogue, page 25.

This report is concerned with the dek planning of a voyage of a VLCC through an area which is relatively unknown, to see what is

involved in such planning on the part of both the ship owner's fleet management and the master of the ship., although most

emphasis has been laid on the planning required from the fleet

management. It also specifies what information is necessary

and whether or not this information is available on board.

This type of planning is normally performed in a rather general manner but sldom or never in as much detail as is shown in

this report. It was felt that the TULA case provided a

perfect example of poor ship-

_an4

shore-base4 planning

con-tributing significantly to the grounding. Tb appreciate the

circumstances which created the need for this report it is recomeflded that the above investigation and analysis be

re-viewed by the reader.

Each chapter of the present report suarizes a particular

area of the planning as indicated by its title. The similarly

named appendices show the planning down to the smallest detail including information derived from the South American Pilot1, charts and other information sources as required for the

plan-- iv

fling of each subject area. For example, more detailed

inform-ation on Chapter 2, section :2.2 is contained in Appendix 2,

section 2.2. Reference numbers used in the text correspond

CONCLUSIONS.. 'AND RE.CONDATIONS

QMuch has been written about vyage planning..' .The available

literature covers almost it:s'entire -range in so far 'as.the

voyages are of. a routine nàture No single. publication

however, covers' the entire 'range of !'routineh' 'voyage planning

but only a specific part Of it. Therefore it is our opinion

that a. guide is:'needed -which .cofers all -aspects of voyage planning, fro the general. directives 'which" should. be, fol:

-lowed to the very Ipecial techniques (of- which some arC

-mentioned in this, report) to -e used.. ,

In this .report', a description is given of planning Of a very

particular.nature, namelythe passage of. a very largevessel.

on a difficult 'and rarely used' shipping route.

It is' hoped that after reading this report it wi-il be clear

that such a case goesbeyond normal planning, procedures'.' It

cannot be assumed. beforehand that the passage can be afely

made. Much of the necessary information is not readily

available. In fact even after our (detailed) piannin; was

completed it still appeared impossible to get more than a,

general notion about whether or not the risks for either

passage are acceptable. To quantify the risk factor mOre

data as well as further development

of the methodology in-

-volved, in the planning are needed.

To improve this "risk notion" one could look for other areas on the globe with comparable conditions, but for which more

vi

It appeared necessary to develop new thethOds to reduce the.

risks as much as posSible in case the route through Magellan

Strait is chosan. Otie of those methods was the way in. which

the "distance to new course" is determined. Whn there is little searoom available, it is important that elaborations of the ship's manoeuvring characteristics are available on board to assist the master in determining the distance to new

coUrse.. Until now this information was not available..

It also appeared that the normal complement of navigation officers is insufficient for a safe passage through Magellan

Strait. Th:is reinforces the need fot flexibility in the

number of (navigation) officers dependiflg on the' roite.

As will be c'lear from this report, even for the planning of a

normal passage a great many publications are needed to obtain

the necessary information. Planning would be much easier and

there would be less risk of omitting valuable details if the

information were condensed into one publication., per specific

area. This publication should cona,jn.such details as:

- chart information

- winds and currents

- outer dangers

coastal features '

navigational marks (includitig ight towers, buoys, Special

characteiS tics) anchorages

tidal information

radio beacons, radio stations (coastal, port and pilot) wit-h

- v

- major ports: directions, iandarks, navaids, depths,

limitations, restrictions, p.iOtage facilities, regulations.

The information should be well indexed and easily accessible so as to avoid lengthy study to get a particular item

This has been introduced in the revised Sailing Directions of

the USA, Much of' the above-mentioned information, such as:

- radiO beacons, radio stations (frequencies and broadcasting times)

- port entry procedures, quarantine pOcedures, area procedures

routing schemes

- search and rescue information

- checklists fOr passage planning

- distance tãblès

could be presented in a chart, thus further facilitating passage

planning and execution.

Publication of such charts has just been started by J.D, Potter Ltd.,

® Finally, we hope to have been succeSsful in pointing out the need for a careful approach in which nothing is left to chance

and all possible resources are utilised when planning passages

VOYAGE PLANNING

1.1 Terms Of Referetice

The analysis of the. unfortunate grounding of the VLCC METULA on Bajo Satlite near the t4e5teth. exit of the First Narrows

has undoubtedly shown that in the area of planning,

improve-ment is, to say the. least, desirable. The work here presented

ende ours to show what voyage planning means in a case where

both technological and hurn capacities in navigation are

stretched t. their limit. One thing is quite obvious, i.e.:

When aaftty margins decrease, care

- should increase.

This rule. applies to all-, concerned, both decision makers ashore as well as the staff on board.

A somewhat unique aspec.t of this particular case is constituted by. the fact that although Magellan $trait is not strictly

with-in pilotage seaters, pilots can be Qbawith-ined an4 with-in the case of the TUIA. were. actually used.

The question then aise of

how much responsibility tests with oners and masters for

proper' planning for transits-undet pilotage. The answer t

this question cannot be simple and unambiguous, unless

sticks to a purely legalistic viewpoint. - The..master, being

ultimately responsible, will consequently be responsible for

the entire planning from departure berth to arrival berth, including pilotage waters.

However, it must be borne in mind that circumstances can and do differ, depending on the vessel size, the area to be

navi-gated, familiarity with. the area, etc. The nature of the

managerial circstances must also be taken to: consideration when comparing practical possibilities versus legal obligations

on the One hand and generally established practice on the other.

The case in hand, the planning of a passage of a loaded VLCC

through Magellan Strait, is a very special one. The specific

circumstances are:

a) a rarely frequented, difficult fairway in a climatologically

uhfavouràbie area

a very large vessel with difficult handling characteristics

pilots with no previous ecperience o

the hdling

characteristics of such vessels

a flexible fleet allOcatiOn system whereby vessels and.

their árews can be é-rOutCd at very short notice.

It is our belief that tmder the above-mentioned operational

conditions, full .repOh5ibilitfotvOyáe planning rests with

the nagementwhO, f Or êcoiOmicreaOn want tO undertake the

assage. Only thanagethent is in pOition to' obtain all the

relévantdàtãànd, oh the basis of théè data, tO assess

"risk

rus ecOnofrdc benfit

If this asSessment leadS to-the Onc1usion that the 'passage is

feasible, thésters of th

vssèls "ordered" to eeóute the

operation should:

be briefed very carefully

-be instructed to supply feedback information based on

practical experience in the area concerned. This feedback

information should be carefully analysed and where necessary

be used to improve and update the planning or, at the other

-. 3'

The full responsibility for planning a voyage of 'a loaded VL through Magellan Strait rests with the owners, suppárted by their masters, because of the extraordinary conditions

encount-eredon such a passage. The Netherlands Maritime institute

carried out a voyage planning exercise based on the above

conclusion. The. result of this.exercise is cOntained in this

report.

I±i order 'to be able to evaluate the TULA case against the

required planning activity, the data used are those which were available prior 'to the time when it was decided to negotiate

Magellan Strait with VLCCs. We hope that this planning ecample

of a very unique and difficult passage will be a valuable con-tribution which will assist future voyage planners in their Wor[(.

1 .2 General Phi losophy

Before going into any specific detail it will be advantageous

to first define what is meant by voyage 'planning. Examples of

it can be found in:

- Aditiralty Manual

of

Navigation9, Chap.ter V, pages 121-155

- Dutton's Navigation and Piiotihg28, 13th editidn, Chapters

11 and 12

18)

- Shell s Guidelines to Navigation

- The Use of Radar 'at Sea24, Chapter 8 pages 112-129

- "Guide to the Planning and Conduct Of

Passagès"2',

'Mex XII

Exhibit 1 gives a general outi]ne of how to approach the rather

complex process of voyage platining.

Exhibit I : Block Diagram. pf. Voyage Plannjng.

REQUIREMENTS F

-4-VOYAGE PLANNING VOYAGE ENVIRONMENT BEHAVIOURAL CHARACTERISTICS NAVIGATION & SAFETY EQUIPMENT METHODS AND WORKLOAD SHIP Feedback Reporting

H

E)CUTION QUALITY QUANTITY E)ERIENCE CREW

*In this context, referring to the population as seen from the ship, i.e. including both surrounding traffic and coastal populations.

This block diagram indicates that there are 10 major areas of

consideration. Four ãteás. deal with -the- particuiars of the

vOyage and three deal

with

the technical. particulars of the

vessel intended for the voyage. Analysis of these seven areas

will first of all have to be provide an answer tp. the question:

"Is the plannd voyage possible: Xes or

METEOROLOGICAL

OENOGRAPHIC

GEOGRAPHICAL

-5=

If the answer is No, a more suitable sh ip will. have to ..be fod or the rOute will have to be abandoned.

If the answer is Yes, the analysis will have to be pursued in

detail in order to establish:

the ;ethods and .edürE fôf safe navigation

the workload involv4 in safe navigation.

In the final stage en investigation should be made o whether

the three crewing elements match and 2 above or whether

additionalquality, quantity or experience is required.

This planning philosophy is equally valid for. both shore

staff-and ship staff. The shore staff, however, will generally.

con-centrate, on the possibility of the voyge as an açceptab1erik while the

hip staff will, on the other hand, cocrae on

its safe execution and on minimising the risk element

It is obvious that voyages con emplated in new, unknown areas with new types of vessels demand most planning attention.

Rout1ine voyages on regular routes.will soon develpp routine

operting.proçedures.. The executionpf such routjne proeedu;es

should however be meticulous and precise.

One of ithe main objectives in voyage p1aning will alway be

the identification of "areas of constraint", 1 e areas of

exceptional risk demanding more than normal attention, skill and experience This identification process for a voyage such as the one in question, is graphically displayed in Exhibit 2 over-leaf. .

Sill Level

Exhibit-'2: Required Skill versus T1me during:"j

-Vbya'e;'-- 6' -Vbya'e;'--. Normal Available Skill keuired' Skill

Ehibit' 2' indicates that there are two arèá bf the voyage"

under consideration

which

reui're additional skill beyond what is normally available on board." (Skill 'is to be interpreted

as the totality of quality, quantity and experience depicted

in Exhibit I under "crew".) "These areaEàrC 1 undér pilotage,

and2A,

astal; FOr 'area 1' the'additionàlskillrequirèment

is mebr the' pilot. krea 2A" is what 'cOuld be called' an area

of ãtticula± cOtraint which hãs'tO be thoroughly itivesi-gated in order to determine th'e methds And workload Involved in safe navigation and the manpower needed to meet these

requirements. In an area such as 2A, it is notknown whether'

the skill 'requirement will' be met by'thepilot: in thecase of Magellan Strait', itis even most unlikely since at the time for

whi'ththe 'planning i this" report is carried out, 'no' VLCs had

been in the area.' 'Therefore one could be' certain that the available pilots had no experience with VLCCs in this specific'

area. Little was known regarding the ships on which they did build up their experience and whether or not they would have

T-ime

2 4 2

Coastal :' _Land

I Coastal

3 fall 2 2A 3

P Ocean Coastal Ocean

had up-to-date knowledge of advanced equithéntTIiis:togetherL with the very probable language barrier leads to the conclusion

that a Magellan Strait pilot should be used for his local

know-ledge only. Ship handling and navigation should remain under

the exclusive control of the master and his off iëer;.:.;

This report will deal in detail with a passage which involves

two 'such are'as of onst.raint;!. '.The purposei of this 'is..to 4emon St.ràte: the extent and complexity of the prObFems that:. canari.se

insuch'caSe's.H:.'

-"..'--

...

Planning 'of..standard. procedi1rs,!. although just:.s. neceêsary, is len exact'ing and. can eas.ily'be' .dsdUced fron:.non-standard

prOcedutes:b'y a process of

.el.ii.natioñ...-

; _7...,,...

2. - VQYAGE ENVIRONMENT

2.1 General

The specific case under consideration is a VLCC voyage from

the Persian (Arabian') Gulf to Quintero Bay on the acific Coast

of Chile. The planning is concentrated on the passage from

the South-Atlantic to the South P,aci'.c The question is

whether to go round, Cape Horn, or through Magellan .,,Strait. To

answer it, a Very thorough investigation of' 'the circumstances

of'. both possibilities is required.

2.2 Meteoroloica1 Data

In order to make a satisfactory choice between 'the two route alternatives, a detailed review of climate and weather conditions

for both routes is needed. Due attention should be paid to the

occurrence of icebergs and pack ice as a potential danger to

navigation. Contrary to North Atlantic conditiOns, there is

no ice patrol and, due to the very small amount of ocean traffic

in this area, there is also a very limited amount of recent infOrmation on ice conditions during the different seasons.

For that reason we have not only used sources of recent

infotma-tion such as:

- the South American Pilot1) further referred to' as the. Pilot

the Pilot Gharts3

but have alsoinves,tigated sources dating b4c1c,o sailing shlp

an4 pre-Panama

Caxl.-4ay

ti

this area was more frequently

traversed 'by men and ships co1etely'depen4eit or wealet

conditions. The best söurqe proved to be:

DaS. Segelhandbuch f.ir den Atlantischen Ozean4.,

b4s4 On

observations from 1868 to 1908.

Detailed meteorolQgical- descriptions

_i4

data ?re prpvi4ed ir

Appet.dix 2.2. :.

As is wel.i known, the weather can be clas.sifie4 as unfavourabie in many aspects such as wind-fOrce, temperature, precipitation.

and visibility. This is.trüe of, both routes. The Mgel1a1

Strait 'ill obviously offer some shelter fom the devastating

powers of the ocean, but this advantage will -have ..to.be care-fully weighed against the dangers to navigation which will be

encountered there. ., ,. .

With regard to.the, ice conditions, it is considered that thet is no' appreciable difference 'in favour of oneor the othei

roUte. Both routes ar already with..n the ice limits before

the point of divergence is reached (see xhibits 2 1 and 2 2

in Appendix 2). -Bbth routes cross the area with the heaviest'

ice concentration Only a much more northerly route could keep

vessels out of the area where .they are endangered by ice. ,,

-2.3

Qceanoayhic Data

Sea-conditions and-swell data were. also obtained from the sources

10

-and Lumb. However, for the same reason mentioned under 2.2,

i.e. low traffic density, the number of observations appeared to be too small to provide reliable predictions regarding

encounter frequencies. This is necessary to estimate the

con-sequences on ship motions of expected wave conditions, both with regard to speed loss and the probability of structural

damage.

In view of the lack of sufficient observations, we followed a method developed by Professor Warren C. Thompson of the naval postgraduate school in Monterey, California and which was used for a thesis by Edward M.A. Perera in forecasting climatological

wave data for Colombo, Ceylon. The method is based on the

assumption that in the first approximation the wave systems of two open ocean areas can be considered statistically equivalent

if the weather systems for these areas are similar.

Consequently, for the purpose of ship motion analysis, we have used the data for area 2 of Hogben and Lumb (eastern part of

the North Atlantic) as an equivalent area for the period

December to February inclusive. According to the Pilot Charts3,

the frequency as well as the wind velocity (wind-force) distri-bution of westerly winds are sufficiently similar, and the fetch is also large enough to give rise to a wave pattern equivalent to that of area 50 with which we are actually

con-cerned (see also Exhibits 3 and 4).

This same heading should also include dita on currents and tidal streams which are especially important for the passage through

Magellan Strait. Details will be found in Appendix 2.3.

The final results will be used to make a time comparison of the

route round Cape Horn, which involves -delays due to the encounter

.2.4 raphic Data;

-Ej

.

In order to obtain an impression Of the area- tob navigated,

a careful study of the relevant Admiralty Piloit.., List of

Lights, the charts, and other literature is necessary. It is

advisable to use as far as posible material published by the

cotmtry having jurisdiction in the area. Language barriers

may uifortunately sometimes prevent this.

Great attention should be paid to the cautions, warnings and

navigation advice provided by these sources. They are to be

incorporated in the. overall planning of the route. The route

itself should be drain on the charts which will be used for

the actual navigation Of the area. Dangers should be specially.

marked and highlighted, including relevant danger bearings. Courses and, bearings should be recorded on the. chart in three

0 0

digits from 000 to 359

Due attention is to

be

paid to the availability of shore-based

navigation systems and similar navaids and their local accuracy,

i.e. their accuracy along the intended route. (See Chapter 3

and ts appropriate appendix for further information Ton

posi-tioning.)

In this context it must be mentioned that great care should also be taken tO assure the charts' reliability, especially

- -1 1. -.

distance, iththe.routethrpug1 Magellan Strai, which ::V9.veS

delays due to waiting times sincethe passagepf the,First: Narrows is dependent on the tides and should pe.ferabiy be made

in. 4.ghç.

;i:.

12

-in the case unde± ão

ideàtibi whre the vCsei is

of-extreme size (seeAppendix2a4)i

Finally, it hould be noted that the. sailing directions in

the Pilot are based on information provided by the sailing

ships of the middle to late 19th century. Naturally these

directions were suited to the ships of that era, which were. small comparêd to those of today, powered by sail instead Of reliable diesel or steam engines, withou.t radio aids to navi-gation and also without weather information from shore-based meteorological institutes.

Uvsrpoal GLAND LONDON outhempton '050° .0300W 020°W / -> ' 01o,w

I95O . LIsard P&nt 2rw

92ON .00,w

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'

d Ouesa&liI'

''I

-Int-Nereire 0 ire FRANCE 0000 1 Oostei Dunkerque _{Bouogn. B} 0

tj

0 rt (-A,

_flrrcMR

San JuIin Santa Cruz Punta Aren Rio Grande gall. Stro g tidal . oc r f,-om t Strait of

to Id. los (s4os

d,n a MairelS 8it :

Is Di

tanley

= =--= = --= =-- ==-- = =--= = --==

1

=

15

-3. POSITION FIXING IN MAGELLAN STRAIT.

The available pathwidth in some sections iS very small,

there-f öre the demands on the accuracy and reliability othere-f the position

fixes in Magellan Strait are high. Since no other suitable

rádiö navigation systems ae available and because'o the need

for continuous position informtion in the areaS of coüstraint

(see Appendix 7), rãdat plays'- an important role in navigatiOn of the Strait.

Firstly, two independent displays are needed: oe fOr the

pilot(s) and one for the ship's own navigation team! Secondly,

both radars should be in optimal condition. Any malfunctioning

detected before entcring the Strait which could influence

accuracy and/or reliability should be répairèd before entry,

otherwise the passage should be cancelled. The same applies to

the gyrocompass, compass repeaters and azimuth circles, because

visual compass bearings, form the secondary position fixing

method (in someparts even the primary position fixing method)

throughout th passage (see Appendix 7). Emphasis should be

placed on-using t19e tiq4 ijçh.pptimise

_tbe

_{accuracy and}

reliability of pqsitiQn fixing (s-'Appendix3.1).

As mentioned above, the available pathwidth is very small at

some locations. It is necessary to get an idea of what part

of this available pathwidth is "claimed" by theinaccuracy

of the position fixing _{Therefore we have computed the 957}

probability contours of those position' fixes which were

obtained by the nest favourable methods in the thore difficult

part of the passage, from the FirSt Narrows _{o-Cabo Quod}

16

-4.

SPECIFIC VESSEL CHARACTERISTICS

4.1 Theoreticai1y RequiredPathwidth

The theoretically required patn4dth is computed in Appendix

4 1,

which also ixplains that an additional safety margin shOuld be added to this value to arrive at the actually

required pathwidth. This safety ma±gin should provide for:.

- weather conditions

ififluene of ëur±nt

- turning of the ship

- fairway characteristics

reliability of the charts

Since the influence of currentS and the reliability of the

chartsre unknow,it is impossible to quantify the êxáct

safetyrgin

However, it- was cpnsidered useful to compute the. theoretically reqüi±éd pathwidth bècauSè the ratiO between available pathwidtfi and theoretically required pathwidth will still give an idea of where the areas of ëonstraint are.

4.2

Determination Of Distance to Nè Course

The available pathwi4th -iS very sthall at some parts of the

- 17

cause,:an unwanted'off-traek deviation, some investigation was.' done into the way in. which coUrse changes are usually -handled.

It appeared that at present this depends greatly on the ecperi-ence of. the master 'or máte. .It should be noted that the..ship

manoeuvring simulator training courses give no help other than the opportunity 'to gain some. experience. -' The only "niethodical"

approach to course changing seemsto be the of the.

distance to newcourSe (the distance between the.point where

rudder should be given:and the intersection point of. the

'origina1-trckthidthe new track) from the ship's'"turning circle data't. In practice, use of this method is hardly possible because on most merchant vessels the available

turning circle data are restricted to large angles of helm;

these data were determined tO get more insight into the turning capability during mergencies.. FUrthermore, this thod only

provides information about the istance to new course,.

but'-does not indicate when, where .and how much couitter-rudder

should be given to check the turning motion when approaching

the new course to be steered. Although it appeared that the

effect of counter-rudder on the distance to new course is raher small providing it is applied in time, larger Off-track

deviations result when counter-rudder is applied too laite (see Appendix 4.2).

Therefore, the method given in Appendix 4.2 was developed to assist masters and officers, particularly those with little

experience. The aim of this method is, not to provide more

accurate values for the distance to new course than are pro-vided by the "turning circle" method, but to allow an "edu-cated guess" to be made regarding the execution of a course change manoeuvre by providing checking times, corresponding

18

-We hope thàt.this method will be helpful in the navigation

procedure traIning on simulators, as well aS on board ship.

It should be stressed, 'hOwever., that "incorrect course changing"

is only oneOf the possible causes of off-track deviations. It

is possible that "correct course. changing" could have caused

certain groundings to occur eariir. For example, the effect

of the error which was the actual cause of such ground-ings could have been counteracted by the effec.t of "incorrect course

changing". This of course should- not justify "incorrect course

ch*nging". ..-

-Finally1 it should be made clear that. the calculations htch

provide the information shown in Exhibits 4..9 - 4.16. will,

because -of their complexity, normally to be dOne by -the

shore-based organization. This again stresses the need .fO±

19

-5. COMPARISON OF ROUTE ALTERNATIVES

As already mentioned, the two route alternatives are through Magellan Strait and round Cape Hon. The following is a comparison of both routes.

.Meteorological Conditions (see Appendix 2.2):

On both routes vety rough weather can be encoutered. In

Magellan Strait, rough weather means mainly squalls with or

withOut bad visibility. When rounding Cape. Horn it means

gales with the possibility of leavy headseas. .

Available Pa.thvi4th (see Appendix 4):

In Magellan Strait, the available pathwidth is sometimes very

sll, especially in. relation to the accuracy of the available

position fixing methods. When-rounding Cape Horn suffi,çient

searoom is available. .

Position Fixing (see Appendix 3)

In Magellan Strait, position fixing is meinly done by means of

.radar and visual, bearings. The- accuracy requirents are.

times very high, because of the little available pathwidth.

When rounding Cape Horn, position fixing is mainly done by means f radar and astro-navigation if the ship is not fitted with SATNAV. It is very possible, however, that the-navigation haS to be baSed entirely on radar observations and dead reckoning,

- 20 =

Required Pathwidth (see Aèndix 4)'.:

The required pathwidths in the areas of consttaint in Magellan

Strait, as computed in Appendix 4, already come very close to the values of the available pathwidths. . Moreover, as

mentioned in the same appendix anxtra safety mergin should.

be added to, the values of the theoretically required pathwidth

to find the, actually required pathwidth. The value of this

safety mergin is not known,'.but owing to the extraordinary

conditions in Magellan Strait, it is a distinct possibility

that." in some places the pathwidth required for safe navigat-ion

might excee4. the available pathwidth.

Voyage. Duration (see'Appen4ix-5):.

As shown below, on average there will be no difference between

the two routes. It.'should, however, be stressed again that

the values in Appendix 5 and the table below are mean values.

The actual values for both the route round Cape Horn and

through Magellan Strait cOuld .tay weli.i.ider those, mentioned

or exceed them.

Exhibit 5:

Variations in th VoyagtigiiBad.on.a

ShIP.speed of '1.5 'c,ots

- Magellan Strait .. Cape Hori

Mean delay owing to .

recoendation in the Pilot

' ..

+lOhr 34mm

Tim loss due tq longer:

'route distance + 6hr 36mm

ilean shorter passage time

owihg tofdlIow,ing current 51mm

Mean' time loss due to

headwaves + 2hr 00mm

Longer.passage time owing to speed adjustment in

areas of consträiht.

.

i- 58mm

Time. loss due to countercurrent

H

+ 2hr OOmi,n

Longer passage tithe Owing

to delay in boarding of

pilots unknown

Time loss due to voluntary

speed reduction uiiknown

Total extra voyage

duration 10hr 40mm

Total extra voyage

21

-Cost:

On the basis of time there is no computable cost difference

other than a possible slight difference in fuel consumption.

Therefore the only cost difference that can be mentioned with any degree of certainty and accuracy is a difference in pilotage and hospital dues amounting to something in the order of

US$102,000 in favour of the Cape Horn route. However, it is

possible that part of these dues may still have to be paid when rounding Cape Horn, because a call is made at a Chilean port.

.22

-6. TIME SCHEDULES OF THE PASSAGE THROUGH MAGELLAN STRAIT

When planning the passage it is necessary to prepare a time

schedule which should start on the intended day and time of arrival at the entrance of the Strait and take into account

the recoendations of. the Pilot concerning the t.me of passage

of the First Narrows. It

IS

also necessary tO:prepare a

simi,-lar schedule starting one day later in case Idiate passage

upon arrival is for some .reason not possible.

There are several reasons for preparing a. time schedule. One

of these reasonS is the need to have a duty divisiOn in order

that sufficient manpower be available when needed. Another

reason is the need to know which section will be traversed

during daylight conditions, and which during night conditions.

This may be iortant in determining the position fixing

methods to be used. A diagram with the times of sunset,

sun-rise and civil twilight for the area wil,l be of help here.

The times for 1974 are given in Appendix 6, Exhibit 6.7. In

the same appendix two examples of time schedules are given:

one for a passage during spring-tides and the other during

neap-tides. The time difference between the two is about

half an hour. This is because of the considerable difference

between the rate of the tidal stream during spring-tides and neap-t ides.

23

-7. TUE AREAS OF CONSTRAINT AND THEIR NVIGATJC)N

In planning, it is necessary tä detèrine where the areas of

conStraint are, aSpecial

Should: be given to thern

From the description of the passage in the PilOt (see Appendi-ceS I and 2) and from the iat-iO of available pathwidth tO

theoet-iëall teuired pathwidth (see Appendix 4 1), it is

clear that there are two areaS of constraint: -

-a-) from abreast of Banco Di-recc-i6n as far as BancO Thit6n

b) from abreast of Pta. Pasaja as far as Isla Beware.

In Appendix 7, these two areas are further subdivided into

different iections, each having its own particular

diffi-culties. Furthermore, a navigation plan and the menpower

requirements are given for each section. One section, namely

the passage. of Bajo Satlite and the 10 fathom patch, haS been

p.anned in detail as it should be done on boar4 ship, and this

is accompanied by the notes which should be written in the bridge

note book and those whih should be inserted on the chart. In reality of course it is necessary to plan the whole passage in

the same detail.

The fleet nagement should plan a passage, such as the one

through Magellan Strait, in-the Same depthof detail as the

navigation plan given in this report. Firstly, this will enable

the nagemént to asSess the degree of difficulty of the passage;

secondly, it enables them to decide on the npower requirements,

8. QWI

Qj$ENTS

When rounding C4pe Horn no additional offloer is required, as

the passage is in fact normal coastal navigation.

However, from the descript-io of the navigation in the areas of

constraint (see Appendix 7), it becomes clear that when passing through Magellan Strait an additional deck officer is needed to allow the captain to asume fui1 responsibil:ity fQr super. vision of the navigation. The need for an additional officer is

also emphasized in the duty diVisipnexamples in Appendix .8,

where it becomes c1er that, depending on th time of entering

the Strait,. t may be very difficult to provide officers who

are fit for duty when needed. Obviously the planning must

be basfd ona capable and well integrated team of officers. Attention should also be paid to the duty division Of the helmsmen, as well as to the refresher training oi these men

during the voyage before the passage.

25

-EPILOGUE

This section concerns the grounding of the loaded VLCC METIJLA (104,378 gross tons, 206,719 tons dwt, drawing 58' 06" fwd,

62' 06" aft) while on passage from Ras Tanura (Saudi Arabia)

to Quintero Bay in Chile. The cargo consisted of 190,415 tons

of crude oil.

The accident occurred at 2216 local time in the First Narrows of Magellan Strait (Admiralty charts 1336 and 1337). At that time the weather was fine and clear, wind westerly, force 3. During the transit of the Narrows the current was ebbing north easterly at a rate of 6 knots and was decreasing in strength. Shortly after the grounding the current started to flood.

Two radars (3 and 10cm with interswitching facilities) and an echo sounder were in operation throughout the whole period

concerned and were functioning properly. Both radar displays

were constantly used by the two Chilean pilots who checked the position of the ship by taking radar ranges and bearings and plotting them on their own Chilean chart 1137. The third mate,

who was 00W, regularly took visual bearings of shore lights and plotted them on the Admiralty chart; later, at the request of the pilots, he moved to the port wing compass repeater and sang out - via walkie-talkie - the bearings of Pta. Mendez Lt. The

master - an ex-pilot in one of the Persian Gulf ports, with experience of all types of tankers, and who had also followed a VLCC course on a ship-handling simulator - checked the navi-gation of his ship on both the Admiralty chart and the Chilean chart. An experienced sailor was on the wheel.

26

-During his stay in Capetown the master had received detailed reports from two other masters from his Company who had already navigated their ships through Magellan Strait on a similar

voyage to Qiintero Bay. TheSe reports had been thoroughly

studied and circulated among deck and engineering officers.

Six das before arfivä. the ter Sent a telgram to the

agents in Valparaiso, Statitig hil ETA at the pilot station

(Baha. PoSesi6n, see Exhibit 6) as 1000 local time. This

specified time was, according to the master,, a very import-aüt factor because 'it would allOw the vSSsèl tO pass through Prirnéra Angostura during daytime So 'that shàIlowS -' covered with seaweed - could easily 'be de'teôted, and also to pàs

Bajo Satglite (see Exhibit 7) with a rising tide almost at

High Water. ' ' H

-The material facts leading up to this accident tete as follows

(all times lOëal): '

.0849: AbOut eightmiles frOth the pilot st4tion.

Rèdeivëd a telegram ith a request to anchor at'

-BahIãPoseSi6n, and alt there for thE two pilOts

-' ' who were expected to arrive at -1900 in an

east--bound' vESSel'

0900-1900: 0ing-to the.strong current (5 khots), the mastEr

dcided- gainstanchoting and instead resolved to keep the Shiptinderway by steaming up and down thE

bay. 'Regiiiarcoi''uniëation with thE-maSter in the

othervessel-wastháintainEd in order to establish a tim&and-a place for embarcation.

-1920: Both ptlots-embaticed-havingbeen transferred from

the other vëssël b means of a' Chilean Naval tender.

27

-o receive

e

pilots, rporte4: to th m4ster, via a wàlkié-taikie, that the pilots had no Objection whatsoever tO navigating in the dark and that pilqtage could be started without

delay.

Position: South of. Banco Narrow (see Exhibit 6).

1930: Full

sea

Sp4 ($0 rpm, 14 knots by log).

1930-2130: Slow progress over the ground (6 knots) owing to

very strong counter-current (ebbing).

During 4iscuss ions with the ,piiots the master learnt that their experience with large vessels did not extend to. Ships oyer 100,OQQ tons.

At 2110 the pilots took up their positions at the

displays,

aking, 'be.rings att.d ranges with

the vajable range markers. Meanwhile, the master, having ,a good look at the new Chilean

chart provided by: the pilots, iloticed a 14m/15m

shliqw patch on it.. To idefltify this shoal on

the ship's working qIar-t he

anfeed its

lati-t.ude an4 .longitude frorn the Chilean chart to

Admiralty. chart 1337. The result was that the

patch fell apparently exactly on the reco ended track shown on the Admiralty chart (in fact, this

patch is correctly shown on the,

ialty cart

sot1 of, the'recoiended track, see: Exhibit 7).

The master later,noticed that there was a

dis-crepancy of about 6 cables between the, grid

systems qf the two charts5 but the 4iscovey was nevertheless upsetting.. He fel.t thathe could not

rely further On the. Admiralty chart. He had also

lost valuable time in checking the navigation carr:ied out by the' pilots.

2130: Entered Primera Angostura.. Pta. Delgada abeam a.t a

distance of 1.2 miles. Course 225°.

28

-2208: 3rd Mate took station at the port wing compass

repeater and sang out the bearing of Pta. Mendez: 063.5°.

2210: No change in the bearing of Pta. Mendez: 063.5°. Radar bearings taken by one of the pilots gave a position slightly to starboard of the recommended

track on the Chilean chart.

2212: No change in the bearing of Pta. Mendez: 063.5°. Radar bearings taken by the pilots gave a pos-ition further to starboard of the recommended track. Pilots gave order to alter course to 2420. 2214: Ship started to turn to 2400.

No change in the bearing of Pta. Mendez. As the master now sensed that something was going wrong

he ordered the wheel to port. At about the same

time he looked over a pilot's shoulder into one of the radar displays and noticed that the near-est coast was just a little more than a mile away. 2216: While the master was transferring this distance

to the chart, the ship ran aground. Stop engines.

As a result of the grounding considerable leakage from the f

or-ward and bunker tanks took place. Two days later, on the flood

tide the ship swung round from 2300 to 1850 damaging more tanks

and flooding the engine room. The overall damage was enormous.

47 days later, after pumping out about 90,000 tons of oil, the ship came afloat, was towed away and later sold for scrap. No personal injuries were incurred.

At a subsequent investigation it was found that the master was partly responsible for the accident although there was no doubt

that a great deal of the blame can be attached to the actions of

Cerro Oireccidn Pta. elgada 2130 Pilots on board 1920 ₁₉₀₀

Se'Orawing

No.7 69°W

..-J

0800 07.00 68030W

SOUTH ATLANTIC

OCEAN

C.Virgenes.

Pta Dungeness

.%--0800

5220S

52°30 8 rt tn!

62°308

52!358

SOundings

...a..J.

_{- ...} .

..

in fathoms

-.

fathom

tErn) This -8

.(14m/

-...,,.

... . ..

patd, it hôwñ

as 52i6"3S,

coPra5pOnti. / .

-Position of Grounthnq at 22 16

I

/

/

. Racon .

ii

I

22 i

,"

-$3

/1

/2'o

-I

/..

4_,i.

-'

/

\

\

Pta. Satélité -, b

\,

Satelite Bank

,ç,#'

\..

,';1;#1:;A

on the chilean c/1rt 7137

69°46'.9W which apparently

--

-

_t

-. I

-/

-- : 69°50W

89°40W

1. VOYAGE PLANNING

1. 1 Description of. the Routé. through MagellanStrai.

(from the Pilot)

Anchorages:

SW of Pta. Dungeness:

Bahia Posesi6h:

Puerto Sara:

Rada de Pta. Arenas:

Further west there are

Descri2tionof Navation Points:

C. VIrgenes:

C. Virgenes. Lt.:

Between C. Virgenes an Pta. Dungeness:

Pta. Dungeness:

exposed to wind and tidal streams; bottom: mud and sand.

exposed to stong tidal streams and S winds;, good holding grqund. exposed to tidal streams; bottom: sandy.

sheltered from W winds;

bottom: mud, sand and in some places rock.

no iuitable anchorages.

height 41m; marked by white cliffs

forming the seaward termination of a. range of hills of moderate

eleya-don; radar conspicuous at about 25m.

white,- metal framework light er,

central colu with black bands,

26m in height; a red brick dwelling at the base of the tower.

a conspicuous white house iith red

roof; 2. cables .N a 41m high st.

the extremity of a low spit of

gravel and sand, 3'n S of the foot

pf a. range of hills (see view, chart 1336).

APPENDIX,

-APPENDIX I Page _2 Pta. Dun.geness Lt.: Cerro Dirección: C. Direcci6n Lt.: C. Orange: C. Orange Lt.: Pta. Delgada:

situated on the point;. round metal tower 25m high, painted red with white bands; a beacon (pyramidal, red with white bands, 16m high)

close to and E of the tower.

Pta. Wreck: . . conspicuous flare.

C. EspIritu Santo: a steep white cliff, 58m high,

difficult to distinguish except from the Strait.'

C. Espiritu Santo Lt.: meta) frawork tower, white with

orange bands, concrete base, 7m

high.

C. Posesi6n: ' bold and sheer headland, 112m high;

from a distance of 15 to 20 miles E. the cape appears as an island (see

view,, chart 1336).

C. 'PoseSi6n Lt.: urn high, white square masonry tower, 6 cables WNW of the suit of the. cape.

68rn high, appears as island, together

with anOther hill S of it, when apprqached fr, the E (see view1

chart 1336).

round metal tOwer, red with 'hité bands,, 2m high, on the summit; a 'beacon (pyramidal, red with white

bánd, red globe toprnark, 16rn high)

close NW of the light tower.

sharply pointed conical and sandy hill, 41m high, unmistakable, app-roached from the E, a white patch

will be seen on its E side. rnetal framework tower, aluminium colour, lOrn high, on the summit;

Some brilliantly lit oil derricks

are SSW of the light toer.

'identified by the light tower on it ànd'the' small settlement in its vicinity.

APP .NDIX '1

Page

Pta. Delgada Lt.: round tal tower, white with orange

bands, lZm,'in height, on the point;

white house with orangeroofand a ' mast nearby; a prominent flare near

the Light tower, approaching from the E the flare obscUres the light.

Sometimes two leading lights are shown for the lighthouse tender.

Cerro Angulo (Angle Hill): 31m high, very prominent, same

appearance as C Orange, no

light-house on it. Pta. Mendez Lt.:' Morro Nuiez: Pta. Barrancã: Bajo Satlit'e: Pta. Baxa:

on the highest cliff, on theS side

of the'narrows (elevation 28w); rotd

metal tower, red with white bands, 2m in height.

2 miles SWOf Pta. Delgada,

con-spicuous triangular, cliff, 22w

high..

Pta. Satlite Lt.:. '- red metal framework tower', 5w. in

height, situated on the point

identified by its lOw cliffs, which are the only ones in the vicinity (see view, chart 1337); a.'beacon: (metal pyramid, red, two white cylin-drical cases topmark, lOm in height)

stands on the point at an elevation

of 16w.

covered by a red sector of' Pa'. 'Delgada

Lt. between the bearings 039 and

0

044 ; SE edge of the shoal s steep

to but is reported to be extending; it is marked by kelp, which may be run der from half flood to half ebb.

when approaching from the W' it- iS

the fourth cliff from the S, mile

NE of 'the point.

Pta.. BaxaLt. '

' a round, metal light tOwer, 3m in height.

C. Gregori'o: sandy and terminates in a small, 4m

APPENDIX I Page 4

PuertO Sara: oil terminal and oil storage tanks.

Puerto Sara Lt.: Cerro Cono Lt.::. Pta. Grãcia: I.Sta Nagdalena: I. StaMagdalena .Lt.:. I.. Contraniaestra: Pta. Gente: Pta. Arenosa:

on a wooden post at the head of the

pier,- lOm elevation.

round metal tower, red with white

bands, 3m in height on suit of

CerroCono, a.distinctive hill,

41m high.

53m high, cliffy (see view 35 in

Pilot).

C. San Simon: highest cliff on S side of Segunda

Angostura, 64tn high.

Monte Agudo: remarkable conical peak, a good mark

until C. San Simon can be seen.

Segunda Angosttira Lt.; 4. miles SE of Pta. Gracia; white

concrete tower, 5m in height.

C. San Vicente Lt.: - square, white concrte tower, 3m in

= height, Situated mile NE of the W

extremity of C. San Vicente (56m

high).

I. Sta Nrta: sheer cliffs, elevation 19m, flat

suimnit, slopes slightly to the E. 40m high at its W end, whete it rises vertically from the sea.

white, circi ar metal tower, 13m in

height; dwelling close by.

15m high; light frorn round concrete

tower, 6m in height. Light is weak

and easily confused with the light-buoys S and E of the island.

22m high.

projection of low land, consisting

of sand and gravel covered with grass and bushes; 4 illuminated, very prominent radio masts, 4 cables WNW-of- Pta.. Arenosa (see chart 1337).

Nuela Prà.t. Lt.

(Pta. Arenas):

Pta. Sta Anna:

Pta.. Sta Anna Lt.:

C. Froward:

C. Ho11and: C. Sàii Isidrb:

C. San Isido Lt.:

Pta. Joaquin:

metal pedestal, 6m in height, at-the

head of the pier. Two conspicuous,

'illuminated radio masts, 3 cables NIE Of Muela Prat (see chart 1281). extremity of narrow. promontory, can

be recognized by a large clt of

trees.

square, white concrete tower, 5m in height, 2 cables WNW of the point.

small peninsula, 1 cable wide, which

joins a low but prominent rounded

hillock (21m high and covered with trees.) to the inland.

white,, circular concrete tower, 8m in height, with red-roofed, white

dwelling close to and NWofit, on

the cape.

a. hillock on it, difficult to

dis-tingui'h from the surromding land

on approach fron N, but prominent when aeen from off C. Froward (see

view, chart 1281).

rises abruptly to an elevation of 359m (see view, chart 1281 and views 36 and 37 in Pilot).

C. Froard Lt..: white concrete colui, 3m in height,

situated on the cape.

steep, bold and prominent, consiSts of a detached ridge parallel to the

shore, 4 miles long, 342m high; the

seaward side has precipitous cliffs, with densely wooded ledges (see view, chart 1284 and view 38 in Pilot)'.

APPENDIX I Page 5

C. Gallant: 25rn high, massive and steep, prominent

from the E (see view 40 in Pilot).

I. Rupert. Lt.: white, circular metal columo, 2m high,

island.-APPENDIX 1 Page 6 Roca Anson: Roca Crooked: C. Crosstide: C. Quod: C. Falso Quod:

C. NOt&:

C. Hunter: 275m high and steep.

I. Shelter:. -prominent with well defined summit,

116m high, steep to and covered with vegetation.

massive and cliffy with deep water

close round it.

'240m high, projects. well' into the

Strait, urimistakable from the E as

it appears to have a cut in. its'

su=it.

when approaching from the W at 'night or in thick weather C. Quod can be

distinguished from C. Falso Quod by

Ite. Beware close to and W of it. very remarkable sheer mass of' rock,

119m high, extremity of small peninsula.

Ite. Cohorti Lt.: round metel tower, white with re4

bands,. on concrete base, 8m in height, situated on 6m high islet.

Moat

of

the coast be1,een Cabo Gallant and Canal Jerónirno is

fringed with kelp and should not be approached closer than 3 cables.

The hazards of Pw2ta Pasaja are reported to project further

into the Strait than is indicated on the chart.

depth -5.2m over it, the kelp on this

rock Shows only 'at lack water because

it is pulled under by 'the tidal streams

(see view B chart 887). C. CrosStide

should be neared to avoid it. The S

extremity of I. Borja Grande in line

with the cut in the suit of C. Quod,

bearing 277°, leads S of Roca AnsOn.

depth less than 2m over it6 marked

by kelp. The bearing O61. of the

sUmmits of I. Borja Grande and I. Borja Chica in line leads. 2 cables

SE gf it. Ite. Beware bearing

295 and open to C. Quod leads SW'

C. Cooper Key: C. Cooper IceyLt.: C. Monday: Pta. Havannah: C. Upright: C. Parker: I. Westminster Hall: Bajo Magallanes: Bah'a Felix Lt.:

C. Cortado:

C. Pilar:

-. round

jfl

shape, not easy to recognise from W except by its light; from E it. shows as a very prominent steep

headland, and in clear weather after

rounding C. Quod, 29 miles ESE, appears as the end of Paso Largd. circular metal column, red with white

bands, 2m in height, situated on the cape (see chart .1105).

bold headland; the cape is formed by

the flat suit of a ridge and

des-cends vertically to the sea; 247m high. sloping projection of bare white

rocks.

flat topped, square faced headland. the termination of. a long sloping ridge with three symetrical

sugar-loaf hills on it, one behind the other above the S hill which is hOrn high; only prominent from E.

precipitous and of granite, 342m

high, remarkable appearance (see view 50 in PilOt).

rocky bank, depth 19.8m over it, steep to, a heavy sea rises on the bank during strong W gales.

round metal tower, white with re,d

bands,. 14m in height..

60m 'high sheer, steep to, unmista-kable from either side.

the sides of the cape are Sheer. and

cliffy; it, is backed by two tmtains

which form a high and remarkable

pronntory. Viewed. from the E, the cape appears to have one double' peaked

suit; the W peak is shaped like 'a

tower and rises, to an elevation of 552rn from the shore W of the cape;

the part of the cape facing the Strait presents a low rounded hill, while its W side shows considerable erosion by the sea.

APPENDIX I Page 7

APPENDIX I

Páge8

Peones Lanchäs Espaoles:

séverãl small but steep islets. lose

to C Pilar, the largest, an enormous detached rock, 93m high, is clearly

seen as a prominent detached islet

from E Shoal water is reported to

lie. 2 miles NW of C. Pilar.

Grupo E ngelista.s Lt.: a white, circular granite tower, I Im

Reconended Track_throuNa.11an Strait

Course of groundtrack Theoretical position of

tobe followed: course.changes:

course 235° till 52°-49'S 068°-0O'W

o

320 Pta. Dungeness 000 6.lnm

290° Cerro Direcci6n Lt. 267° 14. 8nm

267° Cerro Direci6n Lt. 267? _6.7

225° Pta. Mendez Lt. 135° 1.Onm

218° Pta. Satlite Lt. 008° - 2.lnrn

246° Pta. Sat1ite Lt. 052° - 7.2

o 0

229 C. Gregorio 275 I0.5nm

0

257 C. San Vicente abeam

1760 _{I. Sà Magdalèna Lt.} 2780

- 43

210 Pta. Arenas 270

192° Cape I mile SW of C. San ISidro abeam

234° C. Froward Lt. abeam

293° I. WoOd 270° - 2.lnm

312°. Pta. Pasaja abeam

315° Pta. Rowe abeam

- 0

--27-2 C. Quod abeam 0.8nm

302

Nother

spur of I. Spider-abeam 0.9rm

305° Cape 2nm, S of Cooper Key. Lt. (southern

side of the Strait) abeam I.lnm

318° I. Centinela Lt. abeam 2.5nm

297° NW cape of Pta. Felix abeam 3.5nm

309° Roca Qutpost (Grupo Westminster)

abeam 4.5nrn

288°

APPENDIX 1 Page 9

APPENDIX I Page 10

Available Pathwidth in Maé1iTah-Sttait

Abreast of:

.. -.Available pathwidth (nm)>2..0im,

Pta. Dungeness Pta. Daniels Pilot Station Plumper Michorage Pta. .Anegada Pta. Delgada. Pta.. Mendez Pta. Satglite

Bajo Satlite

10 Fathom Patch Banco Trit6n Banco Nuevo C. Gallant Rocas Rupert Pta. Pasaja C. Middleton I.. Cohorn Lt. Roca AnsOn Roca Crooked I. Beware I. Spider' C. NOtch' C. Hunter I. Shelter C. .Pilar 1.8 1.6 1.6.. 1.5 0.8 1.7

00

1.5 i.b.'. 0.6 1.0 i.'0 0.7 0.8 1.2 1.5 1.4 1.5 .00

00

1.2. Influence of Tide.on Available Pathwidth.

The

vicinity of the 10 fathom patch, 6.7nm SW of Pta. Satlite, is apparently the oniy part of the recoéndéd track through Magellan Strait, where the available pathwith is small but

where the risiig of the tifle bight

gie a

Significant increase

in available pathwidth.

-7) . .

-In the Chilean Tide Tables details are given for Bahia Santiago

and Baha Felipe which are immediately north and south of the

10 fathom patch, respectively. It is assumed that the average

of the tidal information for Bah!a Santiago and Bahia Felipe would provide the values for the vicinity of the 10 fathom patch. The tidal curves fot BahIa Santiago and Baha Felipe are found by interpolation, in Table III of the Chilean Tide Tables and

the daily predictions. The fact that Table II. has to serve for

both standard

a'4.

secondary port of the tidetable may, however,

justify some doubts

_as

'o is accuracy.

E,thibit 1. _1: Daily Predictions for Puerto NOtt

Standard port, January 1st, 1975 (springtide):

APPENDIX I

Page 11

-Time Of HWand LW Heights above Gha Datum

03.36 6.86m

10.00 0.52m

16.08

APPENDIX I

Pagi 12 -:

Exhibit 1.2: Daily Predictions for BahaSantiagd atidBàhiaFelipe

Secondary ports (see Exhibit .5):

Conclusion

Addihg the values .of bpth curves (see Exhibits 1.3 änd-14 to the

charted depths near th 10 fathO patch will Shd that the patch

Of about 8 fàthoE of it cannot be pasCd over at an

tié Of

the tide. However, if the passage through Primetà AngOstura

made at the time recoended in the Pilot, the 10 fathom patch wil.l be passed ábüt 2 hoüs before .HW inBaMa Santiago and

Baha Felipe. Consequently the charted 12 fathom depth On the

portside of the recoended track and iediately after the

10 fathom patch, which at low water would be the port limit

of the available path, will be increased by 1.7 respectively 1.9 fathoms to about 14 fathoms actual water depth, which provides enough under-keel clearance not to be a problem at

either spring-tide or neap-tide.

Bahia Santiago BahIa Felipe

Time of HW and LW Heights above Chart Dat

Times of HW and LW Heights above

art Dati - --23.51 (31/12) 06.15 (01/01) 1.2.23 18.26 4.62m 0.03m 3.86m 0.58m 23.51 (31/12). H 06.15 (01/01) :12.23 18.26 5.98m 1.04m 5.22rn ].59m

1.3 Description of the Route round Cape Horn

(from the Pilot)

Generally speaking, the coast of Tierra del Fuego, including the islands lying off it, has not been well surveyed and the

available charts are of very small scale. However, 10 to 20

miles from the land the depths vary from 110 to 365m, the bottom

being sand almost everywhere. Not until within about six miles

of the coast does the bottom become irregular with rocks rising

to or nearly to the surface.

Description of Navigation Points:

I. de los Estados:

APPENDIX I Page 13

mountainous, with its peaks covered

with stiow almost all year round.

Everywhere the coast consists of rocky

cliffs, from 60 to lOOm high. When

passing E of the island care should be taken because the NW-going current

sets strongly towards the island. Vessels are advised to stay at least

10 miles E of the island because of

the very dangerous overfalls, caused by a tidal stream of up to 5 knots

against the wind, of f the E extremity of the island.

Cabo de Hornos (Cape Horn): seen from a distance there is nothing very striking in the appearance of

I. Hornos. Nearby it is more

remark-able, showing high black cliffs to

the S. The Cape rises to an elevation

of 405m (see view, chart 1373).

Cabo de Hornos Lt.: truncated conical wooden tower, 4m

high, on Cabo de Hornos.

Is. Barneveldt: 99m high, nearly I mile long, with

APPENDIX .1

Page 14

I. Deceit:

Is. Hermite:

Is. Ildefonso:

Cerro, Cathedral de York:

Rocas Cabrestante:

Rocas Philips:

I. Treble:

C. Castlereagh:

I. Noir:

44Om high. When seen -from the E,

its outline is not' unlike'that of

I. Bartholo, the largest of Is. Diego Ramirez.. A detached group of pinnacle rocks lies 3 miles off the

SE extremity of the island (see view, hart 1373 and view 14' in the Pilot).

slopes gadually W from the rugge4

heights in its E part.

185m high. Supposed to be the top

of a narrow submerged. utain range.

Vessels can pass derately close to

them, according, to the Pilot. In

1969 the islands wüe reported to lie

3 miles farther S than charted.

Cauti,,on: there

i8

a

.4ifferenc

beeen the charted positions on

the various charts.

resembles the building of that narne 'The island of which it is a part

(I. Waterman) is very hjg1.

the st seaward termination of Is.

Christmas.. It is 6m high with

breakers 2nm seaward of it. The Pilot reco=ends that it be given a berth

Of at least 5 miles.

very low and, dangerous, should be given a wide berth.

the largest of a small group of

islets and rocks off the SW end of i.Londbnderry. The islet has 3 'peaks, and is visible from a

con-siderable distance.

the SW .ettemity of I. Stewart. It

is high an4 remarkable (see view 15

'in Pilot).

-183m high; extends , piles W to C.

'Noir,. rocky pinnacle resembling a tower or belfry at the, extremity of a low point (see view 16 in Pilot).