Preserving plumbing in Port Arthur
Extensive upgrades to the infrastructure at Port Arthur’s heritage-listed penitentiary building has unearthed relics of convict-era plumbing. Deborah Andrich reports.
The penitentiary building at Port Arthur is one of the most photographed historical sites in Tasmania. The site is a key tourist attraction for the state.
The building was converted from a mill and granary as directed by Commandant James Boyd to a gaol and run in a similar fashion to Pentonville Prison in England, which the Commandant was in charge of prior to his arrival in Tasmania. It closed in 1877 when the entire settlement was shut down.
Two major bushﬁres ripped through the site in the 1890s, destroying many of the buildings and caused severe damage to the internal timber framework of the penitentiary, leaving it vulnerable to further decline.
In 2014-15 more than $7 million was invested into the building to provide structural stability and to enable interpretative work to begin to understand how the building and in particular, the rear of the building which was believed to be the ablutions block, was used. The archaeological dig uncovered more than just a few old buttons revealing the original mill and granary drainage system.
Archaeology and heritage is a key factor in maintaining the story of Port Arthur as was the visitor experience.
To maximise the visitor experience and maintain the infrastructure to cope with increased tourist numbers, the Port Arthur Historic Site Management Authority (PAHSMA) instigated a major roll-out of upgrades and infrastructure.
Conducted under the direction of the Conservation and Infrastructure department, project manager Rod Cooper established a list of projects to bring the site up to current standards, given that the last major upgrade was conducted in the 1980s. Chief among those projects were the water treatment systems, ﬁ re services, sewerage and irrigation. Supporting Rod was the Works team, headed up by Marty Passingham, many of whom have worked at Port Arthur for many years and brought to the roll-out a wealth of knowledge and skills.
“During the 1980s, Port Arthur was essentially a small tourist town with residents and small businesses, not the major attraction that it is today,” says Rod.
“Now it attracts more than 350,000 visitors a year. If a large cruise ship pulls in, the visitor population can be as high as 5,000 people on a single day.
“The infrastructure that was laid down in the 1980s was standard practice, but nearly 40 years on, much of it was reaching the end of its life span and needed upgrading to meet building codes. For example, the ﬁ re system carried the potable water and the water treatment plant chlorinated all the water irrespective of its ﬁnal use.”
On the priority list for Rod’s program was an extendable rainwater harvest system to initially store 180kL of water that is reticulated around the site for non-potable uses such as toilet ﬂushing, irrigating the gardens and vehicle and ferry washdown. By removing the demand on chlorinated potable water, the water treatment system’s ability to meet Australian Drinking Water Standards was enhanced for current and future needs.
“The water treatment system deﬁnitely needed an upgrade,” says Marty Passingham.
“Essentially Port Arthur is like a small council in that it provides a lot of services to the surrounding private homes, businesses and the caravan park, including potable water. So as tourist numbers increase so too does the community, placing extra demand on the water treatment system.”
The ﬁre services upgrade was also high on the priority list. The original system deployed in the 1980s was undertaken using technology of the day, but now is no longer adequate or compliant. In a four year period, removal and replacement of asbestos sections of pipework and ﬁttings were replaced along with aging galvanised steel with inert alternatives.
The Conservation and Infrastructure team developed a new set of trenches to install 150mm pipe networks for ﬁre services and 80mm for separate domestic water. While the trenches were open, a new ﬁbre optic cabling system was installed as the copper network was beginning to fail.
“The philosophy of PAHSMA is to maximise the visitor experience, which means as little intrusion by maintenance and infrastructure works as possible,” says Rod.
“The process to get approval to open a trench can take many months, so once we had it open we made the most of the opportunity to install as much as possible for immediate needs and to future proof for down the track.”
Fire hydrants have been placed in strategic points around the site, but are no longer the classic above-ground models, but in-ground turf hydrants. Fire plugs have also been installed to connect portable ﬁre ﬁghting equipment should the need arise. The project was collaboration with TasFire Services with emphasis on managing a wildﬁre event. Static reserve supplies and emergency pumping has been installed along with three power generators with remote monitoring of pumps and wastewater treatment functions.
Irrigation of the gardens is kept to a minimum. Port Arthur is generally wet for nine months of the year, but during the summer months heritage gardens and trees are given water to keep them going.
“Some of the oak trees date back to the early days of the site – so more than 100 years old, so they are given extra attention,” says Marty.
“However, for the most part we let nature run its course. The grass is allowed to brown oﬀ in summer and composting and mulching of the leaf litter is used extensively. Using water on the gardens puts unnecessary strain on the water storage we have.”
The ﬁnal priority on Rod’s list is the sewerage treatment. Although not commenced at the time of Rod’s retirement in 2016, Marty says that it is still the remaining priority. With up to 5,000 visitors on the site in one day, the increasing pressure on the sewerage treatment from the toilets and kitchens is enormous. Currently, treated water is discharged to the adjacent bay via a deep water outlet. The goal however is to upgrade the system to give zero emissions using a bacterial methodology to break down the solids to the point where the water can be used for non-drinking purposes.
ARCHAEOLOGY AND HERITAGE
Port Arthur remains as one of the last few sites of historical signiﬁcance from the convict era in Australian history and consequently heritage and archaeology are a major component of the work undertaken onsite.
Many of the original records of the site have been preserved, but archaeological digs such as that conducted at the rear of the penitentiary building has shed signiﬁcant light on the day-to-day workings of convict life and the quality of the workmanship of the day.
For Rod and Marty the biggest challenges they faced when undertaking the infrastructure rollout was to preserve any new artefact they came across for the archaeologists and historians to examine and record. All new non-metallic pipe systems have been installed with stainless steel trace wires in the trenches to facilitate future electronic detection; often parallel trenches to the original were used.
“Before we physically opened up the ground for any trenching, extensive archival research was undertaken and relevant external approvals either at a state or federal level were obtained. It was not unusual to encounter heritage artefacts not previously catalogued meaning that work stopped immediately until appropriate processes were in place,” says Rod.
“Sometimes it might be a clay pipe, or building foundation, lead water pipes or stormwater drains. It then became an archaeological dig and might stay that way for several weeks while it is fully recorded.”
Both Rod and Marty applaud the workmanship of the early convict years.
The penitentiary building was originally designed to be a granary and mill and the aqueduct to supply the water to the waterwheel was about 1.6m high, and 0.75m wide, conducting water from a reservoir (now redundant) across a road via an overhead pipe to the waterwheel. The system has been partially preserved but is not open to the public.
The archaeological dig of the penitentiary building has found evidence of hard-wearing sandstone that directed water run-oﬀ into box drains for the laundry, bathhouse and wash stations. The ablutions drains and seating brackets have been discovered under the laundry which was extended in later years.
“The quality and workmanship given the limited resources is remarkable,” says Rod.
“Much of the sandstone was quarried from a hill behind the site, hand cut, transported by a tramway system, shaped by masons and put in place to create various building elements. The engineers of the day sized it properly to cope with the stormwater. In one year we had 55” of rain (1,200mm) – those heritage drains can still deal with it. Given the era in which it was built, line of sight and boning rods were the accepted surveying methods of the day to get the levels. It is a remarkable skill and workmanship.”
Heritage trade skills are an important part of the Works team, says Marty. Understanding how to build the sandstone box drains is the realm of the plumber, but it is the stonemason who needs to repair it. Likewise for the rooﬁng on the heritage cottages – the plumber needs to understand how to undertake the lead ﬂashing and guttering, but it takes a specialist to replace the shingles on the roof.
“Mainstream skills are moving with advancements in technology – both in materials and systems – taking us further away from traditional skills,” says Marty.
“Never before have we experienced that loss of knowledge of those old practices. Port Arthur is one of the last places that still uses those skills. We make our own lime washing and lime mortar as there was no cement or modern plaster used on site. These skills have been around for hundreds of years and we actively support training courses to preserve those skills.”
While the World Heritage listed Port Arthur Historic Site continues to be a major tourism asset for Tasmania, the need to preserve the history is also under mounting pressure. Maintaining the visitor experience is an important aspect, but increasingly, so too is the preservation of heritage trade skills and conserving and presenting the site to the current high standard expected of a World Heritage listed place.