Author Archives: Hamish Williams

Walk this way

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Lyttelton is a fun and exciting place to do archaeology. I’ve been lucky enough to get to do a bit of archaeology in Lyttelton in the last few months, mainly out in the road, because of the digging that’s been going on for the installation of new sewer pipelines. Once completed, these pipelines will make Te Whakaraupō / Lyttelton Harbour a much happier and healthier place: for the people, for the fishes, and for the mermaids. Although road formation archaeology (concerned with exploring how historic roads and their footpaths were formed and have changed over time) is not necessarily the most glamourous subject of archaeological enquiry, I’ve become rather fascinated by it lately, and so I thought that I’d share.

Built on the steep sides of an extinct volcano, Lyttelton’s topography presented all sorts of challenges for 19th century roadbuilders. It’s much easier building a road on the flat – Christchurch was lucky in this respect, (even if their roads had to be formed across swamp). Lyttelton had it tough – building roads on a sloping terrain is so much trickier. Civic authorities had to first work out the best levels and gradients for the roads to be formed at, so they could then work out which parts needed to be cut down, and which parts built up. Many of these cuttings needed to be supported by retaining walls so they wouldn’t collapse.  Drainage was especially important, so the roads and retaining walls wouldn’t wash away in bad weather. The steep gullies that ran through the town were perhaps however the biggest of challenges that faced 19th century road builders. These gullies carried stormwater off the hills into the harbour – and in many places were impassably wide and deep. Stone culverts and brick sewers were laid along the length of them before they were all filled in by the late 1880s; often with clay and rock derived from road formation works that were happening elsewhere. And then of course there are those flat parts of Lyttelton that were reclaimed from the harbour – where precious flat land for roads and port infrastructure was created not by building up or cutting down the existing terrain, but by building outwards from the edge of it, into the water.

The 1880s red scoria retaining wall on Brittan Terrace, Lyttelton, exposed in section. This was one of my favourite 19th century retaining walls that I had the pleasure of recording with SCIRT, during the course of it being repaired and rebuilt. Image: Hamish Williams.

A small section of the brick barrel drain on Hawkhurst Road, Lyttelton. This drain was built in sections throughout the 1870s and early 1880s down the side of Salt’s Gully, before the gully was filled in and Hawkhurst Road built on top of it. Image: Hamish Williams.

Road formation stratigraphy exposed underneath Norwich Quay, Lyttelton. I could determine that there was at least five different road surfacing events, because there were five different layers of rocks laid down one over top of another. Image: Hamish Williams.

Road formation stratigraphy – the differential layers of gravel, stones, and rocks laid down in times past to surface the roads before they were sealed – is at the best of times pretty hard to interpret. Unless diagnostic artefacts are found in association with particular layers, when exactly these layers were laid down is notoriously hard to pin down, even when you have historic records to help you make sense of it. Every now and then however, strange and unusual things, (or things that are strangely familiar) surface that are a little easier to make sense of and date – like the Norwich Quay crossing.

The Norwich Quay crossing

By 1860 the two main thoroughfares in the port town, Norwich Quay and London Street, were formed, in places with rudimentary footpaths on either side, but most other roads were little more than rough tracks cut through the tussock-covered hills (Rice 2004: 26). £30,000 had already been spent by the Provincial Council in forming the Sumner Road by this time – the critical overland goods route between the Lyttelton and Christchurch – but locals were irate that they couldn’t just walk a little distance down the road to the shops without having to inconveniently wade through mud. “Norwich Quay is a filthy slough, Oxford Street worse than any newly ploughed field, and London Street an alternation of watery mud and muddy water” reported one local (Lyttelton Times 23/6/1860: 4).  In 1874 the footpath along Norwich Quay was reported as being “in a totally disgraceful state, and totally unfit for ladies”, who shouldn’t have had to make their way through ankle deep mud to get to the railway station (Lyttelton Times 5/8/1874: 2, Globe 6/8/1874: 2).

High leather boots up to the neck indispensable. Must have been pretty bad. Image: Star 29/6/1868: 4.

Trenching along Norwich Quay, approaching the Oxford Street intersection, looking east. Image: Hamish Williams.

In early June, I found some evidence of how different sections of the Norwich Quay roadway had been built up over time. Some of the most interesting road formation archaeology was uncovered at the intersection of Norwich Quay and Oxford Street, when the sewer pipeline trenching was passing through. Historically this has always been one of Lyttelton’s busiest intersections (and it still is today). Here was the location of the Post Office (built 1875), and on the opposite corner the offices of the Lyttelton Harbour Board (built 1880). You had to pass through this intersection to get to the wharves and jetties, and the railway station and gasworks was only just down the road a bit. Here evidence of historic road formation layers were well preserved beneath the modern asphalt road surface. Crossing at right angles to the trench and in perfect alignment with the footpath on the eastern side of Oxford Street, was exposed the remains of what turned out to be an old pedestrian crossing. Today pedestrians are spoilt for choice with three pedestrian crossings at the intersection to choose from, back in the 19th century they had just one.

Lyttelton. Burton Brothers Studio, Dunedin, NZ. Image credit: Te Papa (C.011652). Looking south along Oxford Street, this post-1880s photograph of the Norwich Quay intersection shows the Lyttelton Harbour Board offices at left, and at right, the Lyttelton Post Office. The pedestrian crossing can be seen at left.

The stone pedestrian crossing as first exposed by the hydro excavation team. Image: Hamish Williams.

The hydro excavation team found it first, at days end and at shallow depth when searching with water blasting wands and suction hoses for all the important pipes and cables that were not to be damaged by the digger. Only a small patch of the crossing’s stone cobbles (or setts – to be more accurate) was exposed – so I went to work to expose the rest of it. These were covered in a very hard, compacted gravel that was covered with a very sticky, stinky coal tar – not very easy stuff to dig through. Trading in my trowel for a 4-pound mallet and cold chisel, I managed to get only perhaps about half of it exposed before it got too dark to see what I was doing. Those short winter days, roll on Summer.

Half of the stone pedestrian crossing that I excavated by mallet and cold chisel in the failing light of a cold Winter’s day, looking north. Image: Hamish Williams.

The next day, as the digger punched through the stone crossing, I was able to confirm that it was approximately 1.75 m wide, (the same width as the footpath) and had been made from dark grey basalt rocks of various sizes firmly bedded into the underlying natural loess clay. The top of the stone crossing was not flat – instead it had a bit of a curvature or camber to it, which would have helped it to shed water when it rained. The rocks that made up the centre-line of the crossing were taller and were bedded deeper into the clay than the rest. This certainly would have made the whole crossing a lot more durable. Historic records suggest that this stone crossing may have been buried around 1914, after the Lyttelton Borough Council decided to spend big money modernising its streets by tar sealing them (Lyttelton Times 14/10/1913: 8).

The stone crossing in section, looking north up Oxford Street. I’m a big fan of the fat sticks of footpath chalk, like the pink stuff you can see here, handy bit of toolbox kit for marking out the edges of archaeological things. Image: Hamish Williams.

When was this Norwich Quay pedestrian crossing constructed? It is hard to say for certain, though it appears in a couple of post 1880 photographs– so our best guess is that it was built around about this time. According to an August 1880 newspaper report, the Council works committee had finally decided to upgrade all the footpaths around the intersection at this time, a works programme that may have included the construction of the crossing (Lyttelton Times 4/8/1880: 6).

The Oxford Street Norwich Quay intersection today, looking southeast. Image: Hamish Williams.

The Norwich Quay crossing was a fun feature to investigate and record, it reminded me once again that history is all around us. The past isn’t buried deep, it’s there just below the surface. The streets we walk today are the same streets walked by the people of the past – all the streets a stage and all of us merely players.

Hamish Williams

Lyttelton, 1880s. Burton Brothers Studio, Dunedin, NZ. It’s hard to determine from historic photos to what extent people silly-walked the mean streets of Lyttelton in the 19th century, but by the looks of this picture, it appears that people weren’t afraid of just standing around like they were waiting for something to happen. Image: Te Papa (0.031057) [original], Hamish Williams and Zoë Meager [mash up].

References

Globe [online]. Available at: www.paperspast.natlib.govt.nz

Lyttelton Times [online]. Available at: www.paperspast.natlib.govt.nz

Rice, G. 2004. Lyttelton Port and Town: An Illustrated History. Christchurch N.Z: Canterbury University Press.

Star [online]. Available at: www.paperspast.natlib.govt.nz

 

 

Up in smoke: Christchurch Destructor

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At the turn of the 20th century, Christchurch’s rubbish disposal underwent a fiery transformation.

After 50 years of settlement, Christchurch was facing a rubbish crisis that was starting to get people worried. The council’s weekly kerbside rubbish collection service, which had been around for 14 years, was working well, but all the rubbish dumps were filling up fast (Lyttelton Times 23/7/1886: 4). The biggest city dump was located out of town in the sand hills near New Brighton. Thanks to all the fish heads, food scraps, and other tasty morsels that were being dumped here on a regular basis, this dump was also home to a large rat population. In early 1900 there was an outbreak of bubonic plague in Sydney, Australia. There was a genuine fear that if just one infected stowaway rat made it ashore to Christchurch, it could easily infect all the other rats and then everyone would be doomed (Press 26/2/1900: 4). If the dump rats got infected with the plague, and then they migrated into town pied piper style, then it would be game over man, game over.

On a Victoria Street site some time ago I found two pits filled entirely with rat bones, evidence of a local rat eradication program. There were the remains of 34 rats in one pit and 21 in the other. Both images: Hamish Williams.

Attempts had been made at various times to reduce the bulk of all of the rubbish at the dump, and bring down the resident rat population by setting the dump ablaze. It sort of worked, but not very well, and eventually these fires had to be put out (as best as they could) because the smoke was a nuisance. Dump rats would even be implicated in starting dump fires, the little buggers. Rats burrowed through all the mountains of rubbish, and in doing so created little air vents that helped reignite the smouldering remains of earlier dump fires (Press 17/4/1900:6). Nice one dump rats.

Fire was seen as the solution to Christchurch’s rubbish problem, but it wasn’t just a case of starting larger fires at the dump and letting them burn for longer. What Christchurch needed was a machine that was able to burn all the city rubbish in a much more controlled fashion, at higher temperatures, and for longer periods of time. What the city needed, and what the city later got, was THE DESTRUCTOR. Problem solved.

‘Destructors’ were the name given by English municipal engineers of the 19th century to big furnaces that were designed specifically for incinerating all different types of urban rubbish on an industrial scale (Moore 1898). Instead of getting rid of rubbish by carting it away and dumping it, rubbish would be burnt to a crisp in a Destructor, and in doing so would be transformed into a product that was then much less of a problem to deal with, and one that could even prove useful. I think Wellington was the first city in the country to get a Destructor, in 1889 (Press 11/5/1889: 6). Christchurch got its Destructor in 1902. Auckland got one in 1905. Auckland’s Muncipal Destructor building still stands.

Schematic of a late 19th century Destructor furnace. Burn it up, little man, and keep shovelling! Image: Moore 1898.

The Christchurch City Council ordered its destructor from the English engineering firm Meldrum Brothers in August 1900 (Press 28/8/1900: 3). It was a ‘six celled Beaman and Deas’ Destructor that was capable of incinerating both rubbish and night soil. Under normal operating conditions, each of the six cells of the furnace was capable of burning up to 24 tonnes of unsorted rubbish a day (Star 28/8/1900: 1). Because of all the smoke and stench it would produce, the Council had difficulty finding a suitable place to put it. Eventually, they decided to put it right in the middle of town, close to the corner of Manchester and Armagh Streets, a stone’s throw away from what is now the Margaret Mahy Playground.  With much pomp and ceremony, the Destructor was officially opened on the 30th of May 1902 (Press 31/5/1902: 5).

A 1920 aerial photo of central Christchurch. Can you spot the Destructor? It’s the one with the smokiest chimney of course. Image: reproduced courtesy of Christchurch City Libraries: CCL Photo CD 3, IMG0026.

After some 36 years of service, the Destructor burnt its last load of rubbish on 14 April 1938 (Press 14/4/1938: 8). The council then went back to dumping rubbish, though by now this was carried out in a much more organised and sanitary manner. With greater emphasis paid to covering the rubbish immediately after it was dumped, there were now thankfully fewer problems with the dump rats. When the destructor building and its massive brick chimney was demolished the following year, the city lost an iconic landmark of a building, though few would mourn the loss of the Destructor (Press 10/2/1939: 12). Its chimney was the tallest in town, but apart from the odd times when it was out of action and undergoing repairs, it blazed up a cloud of dirty filthy smoke pretty much 24/7.

The chimney was demolished entirely by hand, quite an achievement. Image: Press 8/4/1939: 21.

The Destructor was a cleverly designed furnace. Although it needed a good amount of coal to get the fires up to temperature, once it got going, little additional input of coal was typically required to keep the fires burning – rubbish would be the main source of fuel. Before being tipped into the furnace, the rubbish was usually raked over and given some form of a preliminary sort-through. All sorts of things ended up at the Destructor, but thankfully not all of it ended up in the flames. Some things, like scrap metal and rags, could be separated out for recycling. A pair of frightened kittens that a stoker found tied up in a paper bag one time were saved from certain death, but other animals were not so lucky. Stray dogs and unwanted feral cats sometimes ended up on top of the sacrificial pyre, these poor creatures drowned beforehand in a well reserved exclusively for this grisly purpose (Press 23/8/1905: 8). Large quantities of fish waste from city fish markets proved somewhat tricky to burn. Wet and slimy, incinerating this kind of waste consumed more coal and as such cost the council lots of money. Later they decided that all this fish waste would be better disposed of by carting it out of town where it could be recycled into agricultural fertiliser. This saved the Council up to 35 tonnes of coal per year (Press 16/7/1932: 16). Nice.

Must have been a hot and sweaty job feeding the Destructor, that’s probably why this fella is wearing a towel round his shoulders, so he could easily mop the sweat from his brow. Image: Press 10/7/1932: 17 .

The Destructor didn’t just incinerate rubbish and dead animals, it was a multi-purpose machine that was also the city’s first power plant. From 1903 the destructor’s steam boilers powered generators that produced electricity for the local grid: the power of rubbish lit the city streets at night (Press 1/8/1903: 7). From 1908, exhaust gases from the destructor were piped underground to heat the neighbouring Tepid Baths (Christchurch’s first indoor public swimming pool). In this way rubbish enabled people to backstroke and breaststroke in heated comfort all year round. The waste by-product produced by the Destructor, called clinker, was not left to go to waste either, but proved to be a valuable and useful material in building city roads.

Destructor clinker! Image: Hamish Williams.

I first came to know of clinker after being called out to a SCIRT job on Eastern Terrace, when a layer of the stuff was found by a crew replacing a broken stormwater pipe. It was a real eureka moment for me when I worked out exactly what it was. By 1928, more than 4800 tonnes of the stuff were produced annually, and almost all of it was put to good use by the council in building and repairing city streets (Galbraith 1928). As later SCIRT works confirmed, this clinker fill was laid down all over the place, mostly as a road formation base course, particularly in locations where the underlying natural substrate was ‘peaty and soft’ (Galbraith 1928).

Road formation related stratigraphy, as was exposed in the side of a SCIRT pipe trench in Beckenham. The layer of Destructor clinker is the dirty brown looking layer at the bottom, capped by two layers of modern hard fill. Image: Hamish Williams.

Depending on what it had been before it was fed into and thus transformed by the Destructor, clinker proved to be often quite variable in appearance. Sometimes the clinker was very glassy, black and shiny, (reminding me of meteorites, not dissimilar to the one found by this lucky young fella) and sometimes it was a dirty brown rusty colour (from all the half burnt iron nails and bits of tin cans). More often than not both types of clinker had little inclusions of semi-melted bits of bottle glass and twice vitrified ceramic sherds in it, a strange sight indeed. We didn’t find too much clinker underneath central city streets, but we did find it in the central city around the banks of the Avon/Ōtākaro River. It was found in abundance below those suburban roadways that flank the Heathcote/ Ōpāwaho River. The silty riverside suburbs of Beckenham, St Martins, and Opawa proved to be serious clinker hotspots!

A chunk of Destructor clinker. This one came from a thick clinker layer exposed during excavations for the construction of the Canterbury Earthquake Memorial wall. Clinker had been used to build up the south bank of the Ōtākaro/Avon River as part of early 20th century river landscape improvement works. Close by on the opposite bank we also found (at shallow depth) crushed clinker footpaths. Image: Hamish Williams.

We mostly found Destructor clinker on the road reserve – public land – and where we found it, we usually didn’t find any 19th century rubbish. However, in those few places where we did find 20th century clinker and 19th century rubbish in close proximity, the 19th century artefacts were always found at a lower stratigraphic level. Because we know that Destructor clinker was only produced between 1902 and 1938, this stuff has proved very super helpful for dating archaeological deposits, especially when we find it on private property (curiously it has turned up a couple of times in backyard rubbish pits). Why throw away a bit of rubbish clinker? I guess maybe someone picked a bit of it up from somewhere thinking it was a rare and valuable meteorite, then realised it was just a bit of old burnt rubbish and chucked it away. Just a guess. Any thoughts?

Maybe because the story of the Destructor is a bit steampunk, or maybe because it reminds me about how persistent the people of the past were in finding solutions to the environmental problems that they faced, I find the whole story of the Destructor very fascinating. I like thinking about how resourceful the local council was more than 100 years ago, recycling what they could, and transforming what they couldn’t recycle into something that could be reused in a practical way, while powering the city in the process. Reduce, reuse, recycle – this modern mantra that we all should live by is certainly nothing new.

Hamish Williams

References

Galbraith, A.R. 1928. Report on the Reconstruction and Maintenance of the City Highways and Bridges. Wellington N.Z: Witcombe & Tombs.

Moore, E.C. 1898. Sanitary Engineering: a Practical Treatise. London: B.T. Batsford.

Press. [online]. Available at www.paperspast.natlib.govt.nz.

Star. [online]. Available at www.paperspast.natlib.govt.nz.

Tanks!

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Anyone in the office will tell you that I have a keen interest in military history, especially anything related to the World War 2 period. I like my airplanes, yes (hats off to the de Havilland Mosquito, that twin engine plywood wonder) but I’m also a big fan of tanks. Last week I officially added to my bucket list a visit to the Tank Museum in Bovington. Camp Bovington in Dorset is the birthplace of the tank, and Camp Bovington’s Tank Museum has on display the largest collection of tanks in the world. One day I will make that pilgrimage…

I’ve been thinking about armoured vehicles a little more than usual recently. Perhaps this has been because some large construction sites that I’ve worked on lately have felt a bit like urban battlegrounds, bustling with big machines, and complete with all the smoke, dust, noise, and chaos of an urban war zone set against a ruinous backdrop of a half demolished/half rebuilt city. Reminiscent of that time in 1942 when I stood with my comrades in defence of the Stalingrad Tractor Factory? Hmm, maybe only just a little.

After an epic binge on David Fletcher’s Tank Chats last week, I decided that a blogpost about my two favourite Christchurch tanks was long overdue. First though, a few fast facts about tanks. The tank as we know it was developed in 1915 as an experimental weapon to break the stalemate of the trenches on the Western Front (Lest we forget). The Brits were the first to put the tank into battle, at the Somme in September 1916, where it had some success. The first British tank was called ‘Little Willy’. Little Willy was soon replaced by ‘Big Willy’ (the rhomboid shaped Mark 1) because Little Willy wasn’t long enough to cross trenches (sometimes it seems, size IS everything). Tanks were not actually developed by the Army, as one would naturally assume, but by the Navy, and they called them ‘Landships’. To throw the Boche off the scent, a less descriptive name was adopted as a security measure – tanks. The name stuck. Water tanks as a war winning wonder weapon? Yeah right! Codewords always work in wartime.

Of course, not all tanks are weapons of war, and the tanks that have popped up in Christchurch’s archaeological record in recent times were not designed and built to serve as offensive weapons, though they certainly did play a part in fighting different sorts of battles. So, let me tell you about two of my favourite Christchurch tanks.

The Fire Tank

I had my first run in with one of the city’s fire tanks in a trench on Manchester Street in July 2015, when SCIRT were digging up the road to lay a new water mains pipe. It was well concealed at shallow depth below the road surface, and at first glance I was a little intimidated by its immense size – it was nearly 40 metres long!

The Manchester Street tank, as first exposed. Image: Hamish Williams.

The fire tank on Manchester Street was one of six built by the City Council in 1885 for the fire brigade so they could better wage war against fire. Fire was a serious and recurrent threat to Christchurch in the early years, because so many buildings were of timber construction and they often stood so close to each other. A small fire in one building could very quickly turn into an inferno capable of destroying a whole city block. Because the council did not begin works on developing a high pressure piped water supply system until 1909, at first the fire brigade had to make do fighting the flames with water they got from local wells, or with what could be pumped directly from the Avon River. This was a less than satisfactory arrangement, especially when wells were dry, artesians yielded only a trickle, or worse still, if fires broke out at some distance from the river, and the fire brigade’s hoses weren’t long enough.

Each of the six tanks built in 1885 had a capacity of 25,000 gallons (approximately 114,000 litres) and were capable of supplying water over a radius of 1000 feet (305 metres). Each tank cost £300 to build, and each were served by their own artesian wells (Press 31/12/1884:2). Just completed, in September 1885 the Manchester Street tank was the lucky tank selected for official testing.  It was calculated that the steam powered pumps of the brigade’s two fire engines ‘Deluge’ and ‘Extinguisher’ would be able to drain the entire tank in just over 33 minutes, however they managed to empty it in 31 minutes – quite an impressive achievement (Star 23/9/1885:2, Star 29/9/1885:3). In the following years the underground tanks proved to be an efficient weapon that saved people and property, however they sometimes had a tendency to overflow through their manhole access covers, of which there was one at each end (Press 12/1/1886:2). Even after the fire tanks were to some extent made obsolete – when the high pressure water reticulation network was finally laid on – these underground fire tanks were not forgotten or destroyed, but were retained, held back in ‘strategic reserve’, just in case.

Fire Tank! Image: Hamish Williams.

Well built, the fire tank had an arched roof and brick walls three layers thick, with an internal width of 2.2 metres and a height of 1.8 metres. Despite the efforts of two pumps, it was not possible to remove all of the water from the tank, which had its crown arch broken out so the new water mains pipe could be laid right through its entire length. It was difficult to investigate this feature because of all the water, and because this tank was technically a confined space, our access was restricted on safety grounds. Tanks sure can be dangerous for archaeologists!

The tank, after half the water was pumped out and the crown of the arch removed. Image: Hamish Williams.

The fire tank stands out as a favourite tank of mine not just because of its impressive size, but also because, like many of the 19th century structural features about the city that we have been lucky enough to investigate, it had been built entirely by hand, brick by brick. Furthermore, these bricks had been laid in a bloody great big deep trench that had been dug by hand, in a part of the city where there are elevated groundwater levels. Build a massive underground water tank in a swamp? Best of British to you mate!

The northern end of the tank, after being filled in with hard fill in preparation for laying the new water mains. Image: Hamish Williams.

Ship Tank

Much smaller than the fire tank, the ship tank was uncovered earlier this year at shallow depth in what was originally the backyard of the Occidental Hotel. This 4 ft cubic tank of mild steel had been buried in the ground for use, we strongly suspect, as a cesspit. When the hotel was connected to the city’s newly completed sewer system in 1882, the tank was filled in, mostly with bricks and other building debris that we reckon came from the demolition of the back part of the hotel.

The ship tank cesspit. In the background Angel and Teri are exposing the foundations of one of the hotel’s fireplaces. Maybe a bit more about that feature in a future blogpost folks, so watch this space. Image: Hamish Williams.

Brick rubble in the tank. The foundations of the hotel’s fireplace was built from the same kind of bricks that were dumped in the tank – so there’s a connection there. Image: Hamish Williams.

In amongst the fill of the tank, we found a large cast-iron lid of 480 mm diameter that provided confirmation for us that this old steel tank was in fact a repurposed ship tank, made by John Bellamy’s tank works in Millwall, London. From the 1850s these riveted steel boxes with tight fitting circular lids began, in increasing numbers, to replace wooden barrels for the transport of drinking water and other perishable items in the holds of ships. Ship tanks have been found in numerous 19th century archaeological contexts across the world. In Australia, ship tanks were cleverly adapted for other uses, including rainwater tanks, sheep dips, eucalyptus oil stills and water troughs (Pearson 1992). A John Bellamy tank of identical form has also been found at Lusitania Bay on sub-Antarctic Macquarie Island, where it is suspected to have been used for the storage of penguin oil, of all things.

The cast-iron ship tank lid, marked JOHN BELLAMY  BYNG STREET/ MILLWALL  LONDON. In the middle of the lid is a central bung, which could be removed to allow access to the tank without having to remove the whole lid. Image: Hamish Williams.

It’s hard to say which Christchurch tank is actually my favourite of the two, both have their charms. I think that if I had to choose just one though, I would have to choose the ship tank. Why? Because the ship tank that we found behind the hotel demonstrates adaptive reuse – something that archaeologists always have to consider when making interpretations about things from the past. Over their lifetime, artefacts both big and small can be modified to serve different functions, and these modifications can reflect different owners, ideas, and changing circumstances (among an infinite number of other possible things). An impervious steel tank built for the storage of water was later modified for the purpose of storing poo, well before the completion of Christchurch’s sewerage system meant that on site poo storage was no longer necessary. On top of this, the tank ended its use-life as a convenient place for dumping rubbish. In a similar vein I suppose, the modified ship tank reminds me of different kind of Christchurch tank –the Bob Semple Tank. If the perceived threat of Japanese invasion at the outbreak of World War 2 makes you think about how you can defend New Zealand’s shores when your Home Defence force has no tanks, all you need to do is modify, arm, and armour up a bunch of old Public Works Department D8 caterpillar tractors in a most Monty Python-esque fashion in the local railway workshop. It doesn’t even matter if you don’t have any standardised design blueprints, or if you don’t even know whether it will work. If the enemy don’t arrive, and your underpowered, under-armoured, silly looking impractical tractor tanks end up being the target of public ridicule, hey, you can always find another use for them, you can always change them back.

Hamish Williams

References

Pearson, M. 1992. From Ship to the Bush: Ship Tanks in Australia. Australasian Historical Archaeology 10(1) 22-29.

Phillips, T., 2010. Always Ready: Christchurch Fire Brigade: 1860-2010. Christchurch: New Zealand Fire Service, Transalpine Fire Region.

Press [online]. Available at www.paperspast.natlib.govt.nz

Star [online]. Available at www.paperspast.natlib.govt.nz

Under the rocks and stones there is water underground

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Living in Christchurch, I am grateful for many things, especially the quality of the tap water.  In Christchurch we are very lucky because our tap water is of such purity that it doesn’t need to be treated with chlorine like many cities have to, which means it tastes so good [never fear – the Council closely monitors quality]. Christchurch’s water is so pure because it comes not from river, stream, or desalination plant, but is sourced from natural underground reservoirs called aquifers – water saturated geological substrata that lie at great depth beneath the city. The story of Christchurch water is an interesting one and lately in the office we’ve been talking a lot about the subject, especially after the recent discoveries of some fascinating old wells in the central city. So, grab a glass of two parts hydrogen and one part oxygen and stick around for a taste of what we have learnt about water supply in 19th century Christchurch from archaeology.

The first brick well of 2017. Well, can you feel the excitement? Image: Angel Trendafilov.

Christchurch was quite unusual compared to most other cities as the local council built a sewerage system (this was completed in late 1882) long before it laid on a high pressure piped water supply (works began on this in 1909). Historically it’s usually the other way round – first comes water then comes the sewers, if both of these weren’t constructed at the same time. Part of the reason for this was the fact that Christchurch was built on a swamp next to a river, so finding water was not a particularly difficult task for early settlers.

As things typically are on a swamp, you don’t have to dig very deep to hit the water table, so shallow wells were reasonably commonplace in the first few decades of the settlement. We have found a good number of these shallow wells – mostly of a circular shape, with an average diameter of 900 mm and lined with bricks. The depth of those has varied somewhat. The shallowest we have found was only 1.6 m deep, and the deepest went down more than 3 m. Often however we don’t get to excavate them in their entirety, either because of safety considerations, or because the depth of the excavation means that the bottoms of these features can stay in situ.

This brick lined well took the top prize for best well of 2016, SCIRT found it when they were laying a new sewer mains in Richmond. The bricks that lined the upper part of the well were missing – salvaged for reuse we reckon. Image: Hamish Williams.

On a Lichfield Street site we found a well that was lined not with bricks but with two wooden barrels stacked atop each other. At the bottom of this barrel well was a large block of porous limestone – we reckon this functioned as a water filter. We can only guess how effective this was.

The barrel lined well – the timber staves were very well preserved. At left is the outside of both barrels, and at right after we sectioned it, showing the fill inside. Unlike a lot of infilled wells, this one didn’t contain very many artefacts. Both image: Hamish Williams.

The bottom of the barrel well was filled with fine grey silt not dissimilar to liquefaction silt- was this well abandoned because it silted up as a result of a 19th century earthquake event? Hamish still ponders this – but he will probably never ever know for certain because Underground Overground Archaeology’s flux capacitor is broken. Image: Hamish Williams.

The problem with shallow wells was that they got easily contaminated – many people got crook and some even died from drinking sewage contaminated water. To some extent this problem was overcome by the council banning long drops/privys and their subsurface cesspits, and later with the construction of a proper sewer system, but mostly it was the geological discovery of the artesian aquifer system below the city. Because these artesian aquifers were located super deep, there was a much lesser risk of their becoming contaminated.

When the groundwater in an aquifer is under pressure greater than the pressure that exists at ground level, these waters are called artesians. If the geology is just right, these waters rise up naturally through cracks in the ground to surface as springs. In fact, the source of the Ōtākaro/Avon River and its tributary streams are artesian springs. In addition to fracturing many underground water pipes, the earthquakes also fractured the ground in many places, which allowed new artesian springs to rise to the surface. A well drilling frenzy to tap these artesian aquifers struck the city in the 1860s. By January 1872 a total of 654 artesian wells in the city had been sunk – both on private property and in the street by the council for public use (Weeber 2000: 11). By the late 1870s the water level in the uppermost aquifer, into which most of these earlier wells were sunk, was starting to decline (Lyttelton Times 17/10/1879:6). Once gushers, many of these artesian wells (often also called  ‘tube wells’) were fast becoming tricklers, necessitating the increased adoption of pumps, or the drilling of new wells to tap deeper and more reliable aquifers.

Old artesian wells are reasonably common finds on archaeological sites about the city and typically take the form of small diameter iron pipes sticking out the ground. The tops of these are often surrounded by larger diameter glazed earthenware pipes, which served as well casings or reservoir chambers to which hand pumps or taps would have sometimes been fitted. Often it’s hard to tell conclusively whether artesian wells of this form are 19th century or not. There is often very little difference in form between 19th and 20th century artesians, and, because water mains were only laid on incrementally throughout the city in the early 20th century, the sinking of artesian wells in people’s backyards continued in some places well into the 1950s. I will always remember the first artesian I found on a site. Disturbance from the digger brought forth a small trickle of tepid water (I remember it was a bloody freezing winters day and the artesian waters that came up out the ground were steaming). Left unchecked over the weekend, this artesian trickle transformed the excavation into a small lake, much to the delight of the local ducks.

A ‘dead’ artesian uncovered on a central city site. Image: Hamish Williams.

An old ‘live’ artesian well – left unchecked and unattended, this one flooded the excavation over the weekend. By the time this photo was taken, half the water has been pumped out. Can you spot the high tide mark? Image: Hamish Williams.

Not long ago we found a brick well on a site that had an artesian pipe sticking out the middle of it, and close by, another artesian pipe sticking out of an adjacent rubbish pit. We interpreted these two artesian pipes as possible evidence of the 19th century decline of the uppermost aquifer that most of the early artesians tapped. The brick well was early – maybe 1860s (we could tell this from the bricks) so we are pretty confident that the brick well came first. Whether because the water in this well dried up or the water got fouled, it at some stage thereafter was filled in, before an artesian well was sunk down through the middle of it. Later on we suspect that the water from the artesian started to decline, so a second artesian was sunk next to it, probably to a deeper level in order to tap a more reliable aquifer. What do you think about our interpretation?

At left, rubbish pit, and at right, brick lined well. Image: Hamish Williams.

The rubbish pit and well after being sectioned, exposing the artesian pipes that had been sunk through both these features at a later date. Image: Hamish Williams.

I suppose that the story of how the people of early Christchurch got their water, and how this changed over time is a bit like life. In the beginning things are often easy, you don’t have to work too hard to get what you are looking for – you can find what sustains you just by scratching away at the surface a little. Sometimes however things inevitably change, (often as a result of external factors) so you have to adapt, give up on the old way of doing things and adopt new methods. Start afresh by digging a bit deeper – it can be hard going at first, but the rewards are worth it. When things change again, you just got to dig a little deeper once more, but second time around its always a little easier. Because, like a Zen master, we have learnt from previous experience that by going deeper within, while at the same time being grateful for what nature provides, you can always find a way.

Hamish Williams

 

References

Lyttelton Times [online]. Available at <http://paperspast.natlib.govt.nz/>

Weeber, J. 2000. Watering Christchurch: The story of well drilling and water suppy in Christchurch. Christchurch NZ: Environment Canterbury.