Group 4709 buys Great Central Railway based Thornbury Castle steam locomotive 7027

GWR Castle No. 7027 ‘Thornbury Castle’, based in Loughborough, has been sold to Great Western Society Project Group 4709, based at Didcot Railway Centre.

The castle is currently based at the Great Central Railway and the 4709 group says each of the components of the 7027 will play an important role in current and future Great Western Society projects.

The main component is the GWR No. 8 boiler of 7027.

This is a major hurdle for the 4709 Group, which aims to build GWR 2-8-0 No. 4709. Early indications, sent to RailAdvent by 4709 President Richard Croucher, suggest that the boiler will have to repositioning its brackets to comply with 4709 as well as Network Rail loading gauge, new tubes, new smoker tube sheet, replacement guy wires, changing foundation ring rivets and resolving a problem

Boiler No. 8 will save the project a huge amount of time and money, with a new 47XX boiler No. 7 costing around £800,000.

This purchase advances the 4709 group and means that almost all major components of the 4709 are now purchased by the group.

Credit: Group 4709

In his full statement, 4709 Chairman Richard Croucher said: “The opportunity has presented itself for the 4709 project to acquire Thornbury Castle and with it its No. 8 Boiler,” commented the Chairman. of 47XX, Richard Croucher. ‘The Thornbury Boiler (No 7615) was built in Swindon in 1949. It has a copper combustion chamber which we believe was replaced in 1959 – an initial survey shows it to be in surprisingly good condition . It will take thickness tests, all remain hammer tests, then the scale will be cleaned for better visual examination.

“At this point, we doubt it would be necessary to remove the foundation ring or modify much of the plate beyond the front tube plate,” adds Richard.

Boiler #8 offers a huge saving for the 4709 project – especially in time and energy; current estimates suggest that a new standard 47XX No.7 boiler would cost over £800,000 to manufacture and take up to five years to complete.

Another problem is the construction of the boiler; “Unofficially we have spoken to a number of potential contractors who have hinted at their preference for a steel combustor, while at GWS we would prefer a copper unit. The downside of steel would be the need for a redesign of the entire combustor with the inevitable delays and redesign approval that would entail. We also know that the life expectancy will be shortened, while its maintenance costs will be proportionally higher.

“With the option of acquiring Boiler #8 from 7027 for 4709, the project leaps forward to a point where we now have nearly all of the major components needed to build our Churchward 47XX 2-8-0. “

“A boiler for 4709 has always been a hot topic of conversation,” adds Richard. “Originally the class leader, the 4700 carried a #1 boiler for its first year of operation, but it was generally accepted that it did not produce enough steam for the heavy loads the 47XX was designed to pull. At this time Boiler No. 7 was already under development and No. 1 of the 4700 was swapped for No. 7 as soon as it was completed at Swindon. This proved to be very successful and now all ten 47XXs had #7 boilers on board.”

“So our intention has always been for the 4709 to carry a #7 boiler if possible. With lower loads, it is best to use donor boiler #1 of 2861 in an emergency. Our acquisition of Thornbury Castle neatly obviates this need.

Richard points out that on 4709, the slightly smaller No. 8 castle boiler would not be possible to spot, being a matter of only a few inches in barrel diameter. “It’s hardly a deal breaker and will be indistinguishable from a non-standard. 7 Boiler. Remember that we would still have had to lower Boiler #7 axle by a similar amount, to clear the NR loading jig.

Richard explains; “In the early 1920s the GWR planned to use the No. 7 boiler for a number of other classes, including the ‘Saint’ and the 28XX, all of which then carried the No. 1 boiler. I think we’re going to see something similar happen here.

Following the recent delivery of the two new fully machined cylinder castings together with the new cylinder and valve covers to Tyseley, the next step for 4709 will be the assembly of the two cylinder castings into one block – this work is currently in progress. Classes. Once this is accomplished, the block will be installed in the refurbished donor extension frames from 4115.”

The original plan was to use 4115’s 6 cwt center stay, but the 4709 team soon realized it was far too light for the 2-8-0. Now, once the extension frames have been installed, it will be possible to measure precisely how much the new 2-tonne center stay will need to be machined and when completed, it can also be finally installed on the locomotive.

“It is then planned to raise the front buffer beam in order to make it possible to propose the whole of the front face up to the main frames for optical alignment. We will then be able to take an interest in running 4709, complete the overhaul of the axle boxes and fit the new springs already ordered. In the meantime, the pony truck assembly is being reassembled and will be ready to go under the front end.

“We hope to inspect the boiler later this year, overhaul it and then see it installed in the 4709 frames before too long.”

Jose P. Rogers