WatercraftIn
The old Fremantle Prison Tunnels
Maritime Heritage Site Inspection Report

B. Coley, M. McCarthy, V. Richards

With assistance from P. Baker, K. Holsgrove and G. Gammie
2004
Report - Dept. of Maritime Archaeology
WA Maritime Museum, No 191.

Contents
Acknowledgments ...........................................................................................2
Introduction .....................................................................................................2
Background .....................................................................................................2
Technical Data..............................................................................................3-4
Site Inspection .................................................................................................4
Environment .................................................................................................4-6
The iron/steel vessel......................................................................................6-7
The ‘coracles’? ...........................................................................................8-10
The ‘plaque’ site ............................................................................................ 11
The raft.......................................................................................................... 13
Discussion and subsequent research ............................................................... 15
Conclusion .................................................................................................... 15
Recommendations ......................................................................................... 16
Suggested conservation treatments............................................................16-17
Appendices ...............................................................................................18-20

FiguresFigure 1. Travel in the tunnels...........................................................................4
Figure 2
Plan produced by Dames and Moore .................................................5
Figure 3. Sketch of iron/steel vessel ..................................................................7
Figure 4a-b Sketch and photo of coracles...........................................................9-1
Figure 5. Sketch of area. ................................................................................. 12
Figure 6. Limestone wall ..................................................................................8
Figure 7a-b Sketch and photo of raft. .............................................................13-14
The 1921 Plan.......................................................................................Appendix 1
West Australian Article with photo .......................................................Appendix 2

Acknowledgments
This inspection was initiated and supported by staff of the Fremantle Prison Heritage
Unit, notably Mr Graeme Gammie, CEO, Mr Beresford Coley, Precinct Manager and Mr
Rob Besford Cataloguer.

Introduction
The purpose of this site inspection was to make a preliminary assessment of the extent
and status of formerly submerged remains of what appear to be ‘watercraft’ in the tunnels
at the Fremantle Prison and to produce a photographic record of the sites and any
associated materials.

BackgroundExcerpts: From the records of the Fremantle Prison

Site Name: Prison Tunnels watercraft
File Name: Fremantle Prison Tunnels

File No: MA 503/01

According to records supplied for the purposes of this study, the first wells dug at theFremantle Prison in 1852 served solely to supply the needs of the Convict Establishment.
The town of Fremantle also supplied its own needs by sinking wells, with the ‘Water
House Well’ at South Beach used to fill casks for ships.
In 1874 ‘Water House Well’ was damaged by a storm, forcing ship’s suppliers to lookelsewhere for water. Soon they turned to the Prison as an alternative source and a holdingtank was constructed in the yards at the rear of the Main Cell Block. Pumps, manned byprisoners, were used to fill the tank with water, which was then gravity-fed by pipes,
down through Fremantle, to the Jetties where ships berthed. At that time both the South
Jetty and nearby Ocean Jetty were in operation.
The Prison Records also show that increased shipping produced a requirement for morewater and in 1876 a reservoir was constructed, using Prison labour, on the South Knoll of
the Prison. Prisoners manning pumps filled the tank at the rear of the Main Cell Blockfrom this. Water from the tank was then gravity-fed by pipes to the Ocean Jetty, which bythen had been extended to form the Long Jetty—then the main port-related structure atFremantle.
In 1888 three new wells were commenced connecting with shafts, drives & tunnels
driven underground in the north east of the Prison yard. This stage was completed in
1894. Water from this complex was delivered by a steam-driven ‘beam engine’ capableof raising 15,000 gallons per hour, to a new storage facility at the Prison, called the East
Reservoir. In 1896 a town reservoir was constructed in Swanbourne Street, Fremantle,
using Prison labour and this was filled with water pumped from the Prison. By 1897,
when the entire facility had been completed, a triple expansion steam-driven pumpcapable of lifting more than 1 million gallons per day from the tunnels was in operation.

The focus of the convict labourers then shifted to cutting firewood and stoking boilers
that fed the pumps.
The Pumping Station, located at the northern end of the East Workshop area, was excisedfrom Prison control in 1901 such that the water authority, then the Metropolitan
Sewerage & Water Supply, could operate independently of the Prison. It reverted back to
Prison control in 1910 when both it and the town were connected to the Metropolitan
water scheme, which was supplied from dams in the Darling Ranges.
Little appears known about activities in the tunnels after that time, though a plan dated 5
August 1921 headed M.W.S.S & B.U. ‘Plan showing Drives and Shafts at Pumping
Station Fremantle’ reflects the Metropolitan Sewerage & Water Supply Department’s
continued interest in the facility, possibly as a reserve supply. The Prison continued touse ground water for its own garden needs up until 1989 when it became polluted by an
oil leakage from nearby tanks. This 1921 plan was located when the present-day
Department of Housing and Works took over the entire prison facility, including thetunnels in 1991/92. Using bioremediation, it took until 1996 to clear the pollution fromthe water in the tunnels.
The remains of the water supply facilities and the tunnels themselves have been, in recent
times, the subjects of on-going study by heritage interests, partly as a result of plans tofacilitate public access to the area. It was during this familiarization process that a visit
conducted in late 2003, whilst water-levels were recorded at their lowest. What are
believed to be ‘water-craft’ were seen along with other cultural deposits, some apparently
dating back to the ‘convict-era’. This discovery led to the February 2004 site inspection
below.

Technical Data:
Date of Inspection: 20 February 2004
Personnel:

Fremantle Prison Staff
Mr. Beres Coley: Precinct Manager, Fremantle Prison
Mr.Graeme Gammie: Executive Manager, Fremantle Prison

WA Maritime Museum personnel
Mr Patrick Baker: Photographer, Department of Maritime Archaeology,
Ms Katie Holsgrove: Volunteer .
Dr. Michael McCarthy: Curator of Maritime Archaeology.
Ms Vicki Richards: Conservation Scientist: Department of Conservation, WA Museum.

The Inspection
At about 10 am on 20 February 2004 a site Inspection Team comprising a photographer,conservation scientist, volunteer and maritime archaeologist/historian joined the CEO,
Precinct Manager and other Fremantle Prison staff entering the tunnel complex at the old
Fremantle Prison, now a heritage precinct. The tunnels, with a total length of about 1 km,
are located about 20 metres below the surface in limestone rock. The principal purpose of
the inspection was to view recently located objects, possibly submerged ‘watercraft’, thatwere considered by Prison staff to be of maritime archaeological interest. These had notbeen seen on previous visits when water levels in the tunnel complex were about 30 to 50
cm higher.
This second inspection was doubly warranted given the desire of the Department of
Housing and Works to open the southern area of the tunnels for heritage tours, with aprojected start during 2004. Clearly, all cultural deposits and site works found in thefacility needed to be accounted for before that time. This would require a set of suitablestrategies being established for the purposes of better management and interpretation of
the place, the structures and artefacts within.
Following an orientation briefing, the group entered the tunnel system via shaft S1, acomplex of laddered, plank-covered platforms interspersed with heavy girders, piping
and the accoutrements of earlier decades. Evocative of past engineering activity, it also
included the remains of modern equipment designed to combat the effects of the 1990s
pollution and to ensure that a safe air supply was available. Descending about 20 m to thefloor and then proceeding south towards Shaft S7, the group inspected fixtures located inand at the base of the shaft. Extending up to the surface, this is expected to become themain entry for future tours. Being replete with evidence of past engineering activity,
again its potential as an industrial archaeological site was clearly apparent. From there thegroup proceeded into the inundated regions.

GENERAL ENVIRONMENT
While some of the tunnels were dry others contained varying levels of fresh water. The
atmosphere was damp and the relative humidity was considered to be very high. The
substrate into which the tunnels were driven appears to be strong, well aggregated porous
limestone, which is easily damaged. The water level in the tunnels was relatively low
during the inspection period allowing access to some features and cultural materials thatare usually difficult to inspect when the water levels are higher. Through-water visibility
was surprisingly good allowing objects in the water column to be clearly seen.

Figure 1. Two of the inspection team travelling in the tunnels. (WA Newspapers)

Figure 2. The Dames and Moore plan showing the progress of the inspection team as
described below.

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FOTHERGILL STREET '•The sediment in the inundated tunnels consists of very fine particulate material, which
produced zero through-water visibility when disturbed. It is anaerobic, indicating anessentially ‘reducing’ environment. Hydrogen sulphide and other polysulphides, formedby sulphate reducing bacteria present in the sediment, are released when the sediment isdisturbed, and it is easily detected nasally. In addition, and despite the implementation ofa rigorous clean-up process lasting a number of years following the diesel oil spill
outlined above, there has been a lasting contamination of the catchment. Petroleumhydrocarbons have been physically adsorbed onto the fine sediment particles and they are
released on physical disturbance of the sediment.
Nonetheless, due to the combination of the fresh water with these anaerobic sediments,organic material and to a lesser extent, metal objects are expected to be quite wellpreserved if buried in the sediment and/or totally immersed in the water column.
Where recently exposed by the drop in water levels, the surface of the sediment,
however, had oxidised forming a thin red/brown encrusting surface layer overlying thetypical black, anaerobic sediment. Hence, the exposure of any metals or organics to theatmosphere in the tunnels would cause accelerated degradation of these materials.
Nonetheless, the extent of this degradation is expected to be far less than that experienced
in most other underwater archaeological environments (e.g. the sea).

An iron or steel tank or ‘vessel’Following the inspection of Shafts S1 and S7, the group boarded inflatable rafts andproceeded over water through Tunnel N1 to an area about 3 metres to the north of
extraction shaft S3 about 40m south of S1, the Emergency Extraction Shaft, where a fully
submerged metallic vessel was recently located.
In remarkably clear underwater conditions, a number of photographs were taken from an
inflatable and the remains were examined and measured manually. The ‘vessel,’ which
lay on a soft ‘muddy’ deposit over a hard rough floor partially buried in the sediment,
was an open rectangular metallic structure (considered to be probably iron, or its
derivative steel) 2m in length and 0.9m wide with enclosed ends and 5cm x 5cm safe
edges surrounding the periphery of the vessel (Figure 2). The skin was not concreted andthe metal was in excellent condition, however there were some signs of active aerobic
corrosion. The depth to sediment from the top of the frame on the southern side wasabout 42cm, on the eastern side 20cm and on the north-eastern edge 21cm. On the easternside, a large piece of timber (11cm x 7cm) was located lying directly adjacent to thevessel some 9cm from the top of the frame, partially buried in parts. The timber was in an
excellent state of preservation. It was not ascertained whether this timber was directly
attached to the iron vessel. A small piece of loose timber (N1.1) was collected from thenorthern end of the vessel. Due to the extremely poor in-water visibility, a more extensive
inspection was not performed and therefore, further structural features were not noted andrecorded.

Figure3. Sketch of iron/steel vessel located in tunnel N1 [Vicki Richards].

The ‘tank’ or ‘vessel’ was surrounded by debris, some of it visible and the remainder
palpable through the mud. Samples of materials from and near the vessel were taken,
even though on preliminary indications (metric scantlings, corrosion-products etc., asoutlined above) it was evident that it was of contemporary construction and that it could
have been used to transport materials during the 1990s cleanup.
As the sediment (sometimes knee-deep) was disturbed during the inspection and as
bubbles broke on the surface, the smell of sulphurous gas became evident to all. While
this is common where sediments collect in archaeological and other deposits, as indicatedabove, the oil fumes and greasy slick that accompanied it and covered all limbs, bodies
and recording objects that entered the water were clearly a product of the 1990s oil
pollution and could prove a problem in the future.

From this area the group proceeded by boat via Tunnel E2 to its junction with Tunnel N3
where raised dry ground was encountered. Apparently noted as fully inundated in earlier
visits by Prison Staff, this short tunnel currently comprises both a flooded section to theeast of the landing point just past a plaque set in the wall and a dry section in theremainder finishing in the west at a wall exhibiting drill holes. These were probably in
preparation for further blasting works during the 19th Century.

The ‘prison coracles’
At the northern end of N3 were found two heavily-corroded and very fragile ‘vessels’
that resembled coracles—a form of skin or hide boat stretched over a wicker or similar
frame that has been used in places like Wales and on the Tigris from time immemorial.
They were normally quite small, with just enough space and freeboard for one person andwere commonly found propelled by a single ‘paddle’ (e.g. Hornell, 1982). The ‘prison
coracles’ had a metal ‘skin’ possibly of wrought iron over a part-riveted frame of iron.
Photos were taken of both and they were also sketched and measured.
From their form, mode of construction and much-corroded state, it was considered thatthey were old, most likely dating back to the early 20th Century at least. Further while it
was evident that while they could support the weight of one person needing to keep theirfeet dry (e.g. a guard) they were equally and perhaps most likely used to ferry tools, foodand the like as the prisoners and their guards waded through the water in the complex. In
that respect the term ‘coracle’ could prove problematic, providing the potentially false
impression that they were used to transport people rather than goods or equally possibly
detritus from the tunnelling itself. At present the term best provides an indication of theirform.
Both vessels were very similar, each approximately 1m in diameter. Two iron sheets had
been riveted together with half inch (1.27 cm) diameter rivets to form the ‘bowl’, which
was then riveted to a circular rim one and a half inches (3.8 cm) wide. There were two
curved supporting straps 3.8cm wide running under the base of the ‘bowl’, connected to
opposite sides of the rim providing added strength to the structure.
The conservator’s analysis indicates that they are lightly concreted, as is typical of fresh
water anaerobic iron concretions. Being totally exposed to the atmosphere the vessels
were exhibiting extensive aerobic corrosion and there were significant quantities ofaerobic iron corrosion products (rust) on the surface of each. This corrosion process wascausing the exfoliation of the previously corroded surface layers and concretion. Bothvessels were extensively corroded, fragile and easily damaged.
In addition, there was a length of degraded rubber lying proud of the sediment, directly
adjacent to the more northern vessel. There were also a few pieces of wood lying on thesediment near these vessels. One piece of wood had a carved indentation on one side. The
wooden pieces were encrusted with damp sediment and in good condition. This sedimentlayer would decrease the drying rate of the wood and possibly prevent cracking, warpingand checking.

Figure 4a. Sketch of the iron vessels (1 and 2) and wooden item located in tunnel N3[Vicki Richards].

Figure 4b. Photo of the iron vessels with part of the inspection team. [Patrick Baker].

Though the area surrounding the ‘coracle site’ was ‘dry’ i.e. it was not inundated, theground was soft, damp and quite muddy underfoot, disguising and potentially masking
the presence of smaller cultural materials. Nonetheless it was evident that, as with the stillinundated sections of the tunnels, cultural materials remain in the sediments and in somecases in the walls and attached to the ceilings.
Associated cultural remains at the ‘plaque site’
The group then proceeded back to the junction of the tunnels noting, in a number oflocations, fragments of timber that had apparently fallen from the ceiling onto the floor.
Timbers were still in evidence on some parts of the roof and in one location a squaresectioned fastening, possibly a hand-wrought spike, was seen cemented into thelimestone. A shaft S2, in this general area of tunnel N3, appeared as a wall built ofworked limestone rocks, serving to secure the lower end of the in-fill and closing theshaft.

Figure 5. Sketch of shaft S2 and ceiling E2 area [Vicki Richards].
Opposite was a commemorative plaque fixed to the western wall, its wording barely
legible in the poor light. The shaft opening had been enclosed with large limestone blocks
and mortar. Amongst the joins between the blocks, some pieces of loose slate were also

found. In addition, a square headed iron spike, standing about 5cm proud of the tunnel
ceiling, was located between shaft S2 and the plaque. Timbers were located on the floor
approximately 3m south of the junction with tunnel E2, partially buried with sediment.
These were in good condition and appeared to be in a track-like arrangement.
Examination of the sediments in the water adjacent indicated that, as with the remainderof the tunnel complex they ranged from ankle to knee deep on a rough stone floor andthey also contained timbers and other materials.
Four timbers were located on the ceiling at the very western end of tunnel E2,
immediately before the junction with tunnel N3. The timbers were fastened with square
headed iron spikes, similar to those observed in isolation in the ceiling opposite shaft S2.
Evidently this area was a focus of convict related activity and given the presence of theplaque and the coracles the northern end of N3 may have been the last underground‘face’ worked and/or the closed shaft at S2 may have been the exit to the workings.
Figure 6. Photo of the limestone wall at shaft S2. The plaque is on the wall opposite[Patrick Baker].

Figure 7b. Sketch of the wooden raft located in tunnel E5 [Vicki Richards].
The group then made its way to S1 via NW2 and NE2 returning to the surface.

Post inspection discussion
In a short debriefing en-route and at the surface, it was agreed by all present that thematerials were of historic significance. It was also agreed that with winter still twomonths off, a ‘window of opportunity’ existed of about six weeks, for further work.
Given the ‘dry’ nature of the remains at the ‘coracle site’ and at the ‘plaque site’ it wasagreed further analyses might best be effected by terrestrial archaeologists. In that regard,
Department of Archaeology staff from the University of Western Australia, notably Dr
Alistair Patterson, were already working in association with heritage Architects andPrison staff. They were seeking fieldwork opportunities for their students. It was agreed
that, as a priority, an approach be made to have students, working under the supervisionof historical archaeologists, examine and record the dry areas around the ‘plaque site’ atShaft S2 and north along N3 past the ‘coracle site’ to the wall north. A test excavationwas also considered warranted. It was evident that early rains could bring the water table
up and submerge the proposed area of study and that the prison hierarchy should effecttheir inspection and test excavation in the short term.
It was also considered that to water dredge the sediments in the inundated section of
Tunnel N3 close to the closed shaft S2 and the plaque could provide indication of theextern of the submerged deposits, though the nature of the pollution in the sediments
could preclude diving on safety grounds. It was evident that before any underwater work
was undertaken attention would need be paid to the effect of contamination on diversafety and on artefact handling issues.
The Museum group then left the site at about midday.

Subsequent Research
Following the inspection, the Museum team, through Mr Coley, came in receipt of the1921 MWSS & BU Plan shown in Appendix 1. This was an extremely important
document in respect of the remains examined given the references to the sites mentioned
above. The salient points are:1) The word ‘Dry’ appears at the ‘plaque site’ at the junction of the two tunnels withshading indicating those areas inundated in 1921.
2) The ‘Coracle Site’ was dry in 1921 and it appears marked with three crosses andthe notation ‘Old Gear’. This is in apparent reference to the materials visible on
this inspection.
3) The notation ‘Tablet A’ appears at the plaque site, which again was dry in 1921.
The words written on the plan above it read ‘Notes on Tablet A Excavations forFremantle Water Supply by Prison Labour 1888. Eyre Evans Warder’.
4) Adjacent to the Tablet, again written on the plan are the words ‘Big shaft withdaylight visible’. This is plugged with limestone blocks.
5) On the 1921 plan at the ‘Convict Raft’ site, just into the inundated section,
appears the word ‘Punt’
CONCLUSIONSWith the exception of the ‘modern vessel’ first inspected, the remains all pre-date 1921
and are expected to be convict-related.
While the ‘coracles’ and the ‘convict raft’ may not have been used to transport people,
such as the guards, they almost certainly were used to transport tools, food, lighting andthe like and they could also have been used to move debris from the excavations as
required.
The words Old Gear and Punt appearing in the 1921 plan, indicate that these objects all
pre-date it. That the word Punt appears within the area of inundation and not against dry
ground indicates that it had become waterlogged and had sunk by 1921.

RECOMMENDATIONS
Note: The initial conservation assessment carried out during this inspection was
preliminary and not extensive. The maritime archaeological assessments were alsopreliminary and were conducted in a non-disturbance fashion.
a) Following a terrestrial archaeological assessment of the ‘coracle site’ and the ‘plaquesite’ in which it is expected that the ‘coracles’ will remain in situ and undisturbed, a morethorough assessment of each should be carried out by staff of the Department ofMaterials Conservation. This would assist in the selection and application of the mostappropriate methods of recovery and treatment, if that is deemed the best course ofaction.
b) The same applies at the Punt site. There an archaeological ‘test’ of the landing adjacentis also indicated.
c) A maritime archaeological test excavation of a number of inundated areas could beconsidered if safety considerations do not preclude it.
PROPOSED CONSERVATION TREATMENTS
The Iron or steel tank or vessel
Having ascertained that this is modern and that it will not necessarily become part of thetunnel collection or interpretive facility any decision on prospective treatment of thisobject would await a decision on its future.
The Prison ‘coracles’
These vessels are fragile and will need additional support when they are recovered toprevent any further damage. On recovery the vessels should be placed in water and kept
wet until the commencement of the conservation treatment.
The concretion and corrosion product layers should be removed by the flame
deconcretion method to minimise any further physical damage to the artefacts. Thismethod involves gently heating the outer surfaces with an oxy-acetylene torch, whichcauses the scale to separate from the residual metal with minimal damage to theunderlying parent metal. Assuming the iron alloy is of low quality (not spring steel) theremaining material should be cleaned in a bath of 2% citric acid solution. After theartefacts are clean, the excess citric acid should be neutralised in a bath of 2% caustic
soda solution, then soaked in water to remove any excess caustic soda solution anddewatered with methylated spirits to minimise flash rusting. Finally a protective coating
should be applied over the entire surface. The type of coating used will be dependent on
the aesthetic finish required.
Storage and Display
Following treatment the vessels should be displayed out of public reach, in a controlledenvironment where the relative humidity does not exceed 50% and the light levels are
below 300 lux. If this is not practicable, however, the vessels should not be displayedoutside. Avoid placing the vessels on chipboard or unsealed wood. Any wooden supports

can be coated with a water-based polyurethane finish. Monitor the vessels regularly forsigns of corrosion.
The Punt
The preferred conservation treatment for waterlogged wood is impregnation withdifferent grades of the water-soluble wax, polyethylene glycol (PEG), followed byfreeze-drying. This wooden vessel, however, appears to be in excellent condition andtherefore, total immersion and impregnation would not be necessary. Surface
consolidation by PEG would be adequate to stabilise the outer surfaces, followed by slow
air-drying.
The vessel should be kept wet at all times prior to the commencement of the conservation
treatment. The vessel should be mechanically cleaned of all surface detritus. An aqueous
solution of PEG 3350 (15%v/v) should then be applied to all surfaces. Four to fivecoatings would be the minimum required. The vessel should be wrapped in plastic after
each coat to maximise penetration and minimise drying. Over the course of a few weeks
the plastic should be removed in stages and the vessel allowed to dry very slowly tominimise cracking, warping and checking of the wood. The heads of the iron fastenings
should be protected with a surface coating.
Storage and Display
Ideally, wooden items should be displayed in a mild environment, with conditions
maintained at about 18°C and a relative humidity of 45-55%. As these conditions are
rarely encountered in most situations, reasonable precautions must be taken to minimise
potential problems. Wooden items must never be placed in direct contact with floors
and/or outside walls, which are often damp. Lighting should be kept to a minimum anddirect sunlight avoided. Monitor the wood regularly for signs of deterioration and mould
growth.

Appendix 1

Figure 1. 1921 Part of Plan entitled: Drives and Shafts at Pumping Station Fremantle.
5/81921.
Scale 50 ft to the inch.

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Appendix 1
Part of an article appearing in the West Australian April 6 2004.

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