Refurbishment of East Sand Filter Drain Valve

One of the necessary tasks, at least once each year, is the cleaning of the Sand Filter Ponds, particularly to remove weeds which grow between the base slabs, and any other organic matter. To perform this task, it is necessary to drain the pond to at least the level in the clean water outlet channel. Over the years, the channel drain valve on the east pond, just behind the Gas Engine House, has become more difficult to operate, hence the decision was taken to refurbish it.

To gain access to the valve, it is first necessary to lift a very heavy, steel, cover plate (a hazard in itself) before looking into the 8-foot-deep brick lined chamber. At the bottom of the chamber are two valves, the 6-inch drain valve and a larger, 18-inch, valve in the line between the pond and the east Clean Water Tank. Both valves looked as though they had never received any attention since their installation in the late 19th century.

The valve is on the left hand side, below the drain pipe, in the photo below.

Lubrication and movement of the drain valve proved unsuccessful in freeing it, so it was decided to strip the valve down and refurbish it. Removing the valve completely was not an option as its inlet and outlet flanges were partially buried in the concrete floor of the chamber. The decision was therefore taken to uncouple the valve bonnet from the valve body and then withdraw the valve spade. The six bolts, attaching the bonnet to the body, were corroded so badly that they couldn’t be removed with a spanner and so had to be cut off with a cutting disc. A gas test had already been performed and proved that the atmosphere was safe for breathing and safe from explosion risk. However, it was still necessary to wear breathing apparatus whilst cutting, to avoid breathing in the disturbed dust and rust in this confined space.

Once the bolts had been removed, we discovered that the valve spade was well and truly stuck in position and, although it could be moved in the horizontal plane, it would only move incrementally in the vertical direction. However, a good number of hours later, with the help of chain blocks and an assortment of prising tools, the spade came free.

The spade, bonnet and gland assembly were then taken to the chain store for stripping down, cleaning, and reassembly.

Stripping this unit down required the two gland packing bolts to be removed, again using a cutting disc. These bolts each had a locating lug at one end and two new ones needed to be fabricated.

The valve internals were cleaned and wire brushed in order to more easily facilitate replacement in the valve body and a rubber gasket was fabricated to make a seal between the valve body and the bonnet. The gland seal was repacked with half inch square packing and tightened down.

An interesting feature was the valve shaft. The shaft, has a “two start left hand thread”. This means that the shaft has two threads cut into it at 180deg. apart. With two threads, this means that for every full turn, the nut and valve spade assembly raise twice as far, as a single thread. The thread form, as stated above, is Left Hand – most people are familiar with a standard thread form, i.e. Right Hand. When viewed from the side, a right-hand thread raises from left to right and from the top it screws in, clockwise. A left-hand thread, when viewed from the side, raises from right to left and from the top it screws in, anti-clockwise (we believe that it was standard practice to use left hand threads on water valves and right-hand threads on gas valves in the 19th and early twentieth century). One other feature of the thread is that it has a “square” thread profile. Square threads are used in heavy load applications as they are stronger than a normal triangular profile. Since this shaft is made from brass (or perhaps phosphor bronze), it was in almost perfect condition.  

The valve assembly was then greased and the externals and internals painted with a protective layer. The valve body was cleaned internally and the bonnet, shaft and paddle reinstalled. After proving that the valve operated freely the new, exposed bolts were wrapped in Denso tape, hopefully to make the next maintenance schedule a little easier.

The final task was to cut a hole in the chamber cover plate through which to access the valve spindle, without need to raise the heavy plate, for future operations.

Refurbishment of Lister “D” Petrol Engine

When it was decided to restore the engine and pump the Lister ‘’D’’ petrol engine was a bit scruffy but in fairly good condition. The pump, which is a three cylinder ram type pump of unknown manufacture, was in a sad state with a chunk missing from the centre cylinder wall, which will have to be looked at some time in the future. The wooden frame, which the whole oily mess sat on, was made from rough unfinished timber, strong but not pretty.
First thing to do was to see if it all worked. The engine needed a new cylinder head gasket so a new one was bought along with a new spark plug, high tension lead, and points to revive the electrical system. Once these parts were fitted the engine worked well and drove the pump easily, and after a bit of flushing out and fiddling about the pump worked too, sort of. It was decided that if the pump works lets take it apart and make it work better, and a short time later there it was in pieces. There’s no stopping enthusiastic volunteers on a mission.
All parts were pressure cleaned and a lot of rust and lumpy bits were scraped out of the pump body. The parts were were given a coat of red oxide primer and finished with two coats of Brunswick Green which looks just right. The spinning, whirly, bits were painted a bright red to highlight them, and the pump was assembled. The result was a huge improvement on the original sorry mess.
Now that the mechanical bits were finished, attention turned to to a new frame to compliment the engine and pump. It turned out that Dave Smart had, in his garage, a large red pine beam. Perfect. It was sawn in half to make the frame rails, planed with a planing machine, sanded smooth and assembled with four by four crossmembers. The finished frame was given five coats of marine varnish which brought out the red colour of the wood beautifully.


Wheels and axles from the old frame were cleaned and painted a gloss black and a simple steering mechanism added to the front axle. A draw bar and eyelet was added to the front axle to hitch onto the dump truck for easier moving around.


The engine and pump and a water tank were then mounted on the frame and plumbing added to make a re-circulating system for the water.
The finished setup works well and and it makes the time and effort all worthwhile. We are planning to demonstrate the pump at future Open Days.
We are fortunate to have such a diversity of skills in our volunteers, woodworking, plumbing, welding, machining skills, all were needed to make this project look and work well.

Boiler Test

Following the successful 10 year hydraulic test and the boiler steam test, on Friday 19th June, the Beam Engine was steamed for the first time since the open day in October 2019.

The engine started without issue and we are pleased to announce that the Condenser Pump bearing repair, performed earlier this year, was a complete success.

Bill Wood

It is with great sadness that we report the passing of long-standing volunteer Bill Wood who died in the early hours of Wednesday 22 April at St Teresa’s Hospice in Darlington. Bill brought to the Society a lifetime of engineering knowledge as a marine engineer and boiler inspector. He was a valued member of the Wednesday gang and on open weekends would selflessly give help wherever needed, either on the machinery where he particularly enjoyed the beam engine or in the entrance where he would greet visitors with a warm welcome. His encyclopaedic knowledge of Pressure Vessel Regulations made Bill a natural choice for the administration of our boilers and compressed air plant. He organised boiler inspections and took care of all associated maintenance as well as documenting safe methods of work. For many years Bill was a member of the Management Committee where he acted as Treasurer and Administrator of boiler and public liability insurance. He would often entertain us with stories of his latest dealings with the bank’s increasingly bureaucratic procedures where his calm yet rigorous approach would save the day. However did you manage to keep your cool, Bill? Outside Tees Cottage his interests included Darlington Historical Society and visiting the Scottish Isles. He was also a member of the Institute of Advanced Motorists where he arranged for George Beautyman to give a talk at the local branch a few years ago. It was a very enjoyable session. We will all miss Bill. He was liked and respected by all and a good friend to everyone. We will miss his conversation and seafaring stories told in his Kentish accent which still prevailed in spite of becoming a naturalised North-Easterner. Our thoughts and kind wishes go to Margaret, his daughter Katherine and his grandchildren. Rest in peace ol’ mate.

Water Fountain Refurbished

Tees Cottage Drinking Water Fountain

There has been a drinking water fountain outside the main entrance to Tees Cottage Pumping Station since 1950, when is was installed by the Darlington Women’s Temperance Association.

By 1981 this fountain was looking unloved and perhaps had been disconnected from the water supply.

Sometime between 1981 and the present day the cast iron cowl, located above the bowl, had been removed and left the installation in an even sorrier state.

In late March 2019 the volunteers at TCPS decided to attempt the renovation of the fountain and it was duly removed. Immediately we met with good fortune when one of our members recalled seeing pieces of broken casting under a table in one of our buildings and thought they may belong to the fountain. This was indeed the case and the two pieces of casting constituted perhaps 80 percent of the original cowl.

Utilising the general engineering skills of our site engineer and the traditional skills of the site blacksmith we have reconstructed the cowl and the whole drinking water fountain has now been reinstalled in its original location. Although it would be great to return the fountain to full working order, not least to provide water to trekkers on the Teesdale Way, we have decided that the risk of damage to the installation, or contamination of the water flowing from it, is too great for it to be reconnected to a water supply.

Below is an enlarged view of the plaque located above the fountain:

The fountain was installed by the Darlington Women’s Temperance Association. An internet search quickly revealed that since 2006 this Association has been known as the White Ribbon Association in tribute to the White Ribbons worn by the women of the Temperance Movement. The Association were approached and were in full agreement with the refurbishment of their gift.

Hornsby Petrol Engine, No 48064

This single cylinder engine was installed in the Gas Engine House at the same time as its big brother in 1914. The engine has a direct-drive compressor fitted and the purpose of this was to charge the air receiver to power the start-up of the large twin cylinder engine which drove the pumps which lifted water from the river and sent the clean water out to the customers, both industrial and private.

Also this small engine drives a generator which provided electrical power for the site including the Superintendant’s cottage. This engine was thought to be originally powered by gas produced on site, but at some stage was converted to run on petrol. We suspect that the original magneto was replaced fairly early on, too.

The engine was running in the early 1980s but since then had been standing idle.

In 2017, it was decided that this engine deserved to be seen working again and so a programme was embarked upon, not a ground-up restoration, but an overhaul to get it running again.

The valve-gear was overhauled, cylinder de-glazed, con-rod and piston retrieved and fitted, petrol tank topped-up and it fired up and ran raggedly, but it ran. Over the next 2 years many adjustments were made; valve timing reset (the camshaft was one tooth out on the drive gear), the magneto arm extended and adjusted and still she ran erratically. The mixture was too-rich and we fiddled with the 1920s carburettor, noticing that it ran better on warm days. The carburettor had a facility for warming the evaporating chamber via a water jacket, so hot water was piped from the cooling-water outlet through the carb and it now runs beautifully, hour after hour.

The generator was overhauled, the distribution board dismantled, new stepped resistors made “in-house” and re-assembled and it now produces electricity, enough to power a couple of bulbs anyway. A kettle plugged into the system took all day to almost boil, so we still have to go to the tea-room for our coffees.

So now this lovely little engine can be seen and barely-heard running on our open days.