Progress on the Boulton and Watt – July 2021

And no sooner said than done! The main contract has been let with Century Millwrights and John Vineer has already installed the new steam valve for the Boulton and Watt.

The photograph above is taken looking upwards at the valve from the way in behind the cylinder. The picture shows the new valve with its “floating” flanges either side. Each of these has been fitted with a lifting eye as part of the installation process. The higher 3/4 inch galvanised pipe, with the red handled stop valve, is the new bypass. The lower pipe, with the black handled stop valve, is a drain line. The elegant bronze tap on the steam line, to the right of the new valve, is a connection for the large pressure gauge on the north wall of the Boulton and Watt house. The new main steam valve is about 2 inches shorter than the one it replaced. So, in spite of it’s appearance in the picture, there will be more clearance between the valve wheel and visitors heads than there was before.

We will be repainting the valve installation in a more appropriate colour and Richard Albanese will be looking out some more age appropriate hand wheels from our Museum stores.  Full reinstatement of the removed pipe lagging will probably be put in hand as part of a more comprehensive relagging of the Boulton and Watt. This will include the proper lagging of the valve chest. However, we will look at any temporary measures needed to protect visitors before this takes place. We are considering whether to add a steam trap to the end of the drain line; at the moment it simply discharges into the space under the floor.

So, with a safe and controllable steam supply now available again, John warmed the Boulton and Watt through (the new bypass is extremely effective). On Thursday 15 July 2021, it moved under steam for the first time in nearly three years. This was not in any sense a full run; the engine was moved in a controlled fashion to allow the installation of taller pump end blocks facilitating the work needed to the strap. It may be necessary to add further blocking in due course and the need for this is under consideration at the moment.

Exciting times! A return to steam during the Boulton and Watt’s two hundredth (and first) year now looks a lot more possible.  

Written by Oliver Pearcey