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Trafalgar Way, LICHFIELD, WS14 9FE

The western ring road is meeting Birmingham Road.

Cast iron post by the A5127 (was A38), in parish of LICHFIELD (LICHFIELD District), South of Fosseway junction from Birmingham Road, on pavement, on West side of road. Cochrane iron casting, erected by the County Council in the 20th century. Inscription reads:- : LICHFIELD 1 : : LICHFIELD / PARISH : : FOUR OAKS 6 / SUTTON COLDFIELD 7¼ / BIRMINGHAM 14 : Maker:- : Cochrane & Co, Dudley. : Milestone Society National ID: ST_LFBM01.

From the corner of Upper St John Street.

This is relatively unusual for a Cornish beam pumping engine. A vertically orientated surface condenser with the steam in the tubes and canal water surrounding them in a cast iron tank. Modern power station surface condensers have the steam outside the tubes and circulating cooling water in the tubes. I suspect the surface condenser was used, rather than a jet, due to the canal water being possibly of dubious quality. The bell mouth to bottom right is the condenser tank overflow and feeds the water to a circulating pump that returns it to the canal, warmer than when it arrived. See also Image and Image

This Cornish beam engine was the fourth engine on site and built in an 1873 extension. It came out of service in 1924 but remains preserved, currently by the Lichfield Waterworks Trust that is in the building with the permission of Persimmon Homes. This shows the pump rods on the 'outdoor' half of the beam. The rod closest to the camera on the right operated a pump for charging the air vessel with compressed air. This became disused c1905 when it was replaced with a Westinghouse compressor. The rod to its right near the right hand edge operated the boiler feed pump that took condensate from the air-pump's hot-well. In the centre is the air-pump operating rod. On the left is the main pump that incorporates a fluted balance weight box between the pump rod and the pump plunger below. This weight provided the power to pump the water against a head of 355' at a rate of 2 million gallons/day. The Trust has confirmed that the weights had previously been removed from the fluted weight box and that it is now empty.

Two pumps on the main pump side of the beam centre and mounted below the driving floor level. The closest is the boiler feed pump and draws from the hot well incorporated in the air pump. The further one was disused and supplied compressed air to the air vessel on the discharge main. Its role had been superseded by a separate steam driven Westinghouse compressor. The big pipe bottom right is the eduction pipe taking exhaust steam to the condenser.

The surviving brick engine house contains a Cornish beam pumping engine built in 1873. This is the upper part of the condensing plant that sits in a big iron tank that was filled with canal water that was being constantly returned to the canal by a pump on the other side of the wall to the left. The big pipe in the left background is the eduction (exhaust) pipe bringing spent steam from the cylinder into the top of the surface condenser that is bottom and slightly left of centre. The condensate and incondensable gases are removed from the condenser by the air pump in the foreground that is operated by a rod from the beam. Top left is the boiler feed pump that takes warm condensate from the hotwell and returns it to the boiler. So far, so good! But, the air pump has a large bore pipe to the right that returned to the canal and according to the original drawing it has been extended upward above the level of the hot well to accommodate this pipe. This has led to a very lively discussion both on site and via e-mail. A surface condenser only contains a volume of water corresponding to the steam used by the engine and all this should return to the boiler via the feed pump. As such, it needs a relatively modestly sized air pump and no need to return large volumes to the canal. On the other hand, a jet condenser needs (say) 20 times the weight of steam in injection water and would have a large excess to return to the canal. Furthermore part of the original specification refers to a surface condenser that could be converted to injection if found necessary. Therefore, our best guess is that this is arranged primarily as a surface condenser but could have an element of injection (jet) condensing if needed and that the air pump is therefore oversized relative to that required for pure surface condensing and has an overflow to return excess water to the canal. However, that is an element of conjecture based on available evidence. You may wake up now!