NEW-BUILD NEWS
Didcot confirms No. 7 boiler for 4709
4709 IS BEING BUILT TO FULL MAIN LINE STANDARD, SO THAT KEEPS ITS OPTIONS OPEN
New-build Churchward ‘Night Owl’ No. 4709 will be fitted with an authentic Swindon No. 7 boiler after all, Didcot Railway Centre has confirmed.
The decision ends years of speculation as to what boiler the ‘47XX’ 2-8-0 would carry; hitherto the Great Western Society was also considering using the spare No. 1 boiler from ex-Barry ‘28XX’ No. 2861 – either ‘as is’ or clad to resemble a No. 7 with which the ‘Night Owls’ were fitted.
A No. 1 boiler would not have been inauthentic however, as class pioneer No. 4700 carried a smaller No. 1 boiler from new for two years until fitted with a No. 7 in 1921.
Using No. 2861’s boiler could have saved £500,000 from the final cost, but the GWS decided in late 2019 to pursue building a new No. 7 boiler because “the risks and costs associated with using the older and marginally less powerful boiler from 2861 are thought to be unrealistic.”
Project spokesman and former GWS chairman Richard Croucher said: “It was always our aim for 4709 to carry the large boiler if possible and the No. 1 boiler from 2861 was acquired as a fallback/ contingency, which it still is.
“4700 carried the No. 1 for about two years but with inside steam pipes to the cylinders. 4709 will have outside steam pipes. We will be starting work shortly on drawing up a construction plan and getting estimates, but it is too early to say how much we think it may cost or who will do the work. We do wish to build it in this country though.”
Despite its recent decision to abandon its main line ambitions (SR500), the GWS is not ruling out taking No. 4709 onto the national network.
The society announced in November that it would no longer be running its locomotives on the main line, partly owing to the complexity of making its fleet main line-compliant, and would instead focus on sending them to preserved railways – but has since said that this policy would not necessarily extend to the ‘47XX’.
Mr Croucher said: “I cannot see how things may be in years to come, but 4709 is being built to full main line standard, so that keeps its options open. We are about to cast new cylinders which will bring 4709’s width over the cylinders within the current loading gauge for Great Western two-cylinder locomotives and it will also be within the height restrictions.
“That is the intention of the project team, but a lot of water will flow under the bridge between now and then, and who knows what will or won’t be allowed when it’s finished? 4709 will certainly do what other GWS locomotives are going to do, which is visit heritage railways.”
The Llangollen Railway engineering team working on No. 4709’s bottom end are expected to have completed the hanging bars, spring hangers, running plates and brackets by the end of March, when the ‘chassis’ will be transferred to Tyseley Locomotive Works to be fitted with its new cylinder block, which it is hoped will have been machined and finished by then.
“Once the cylinders are fitted, we will then be able to carry out final alignment checks on the horn guides, measure their final size(s) and on that basis, machine the axleboxes to suit. This will allow us to wheel 4709 for the first time,” said a project spokesman.