Overhaul work continues across a few sites on London and North Eastern Railway Class A4 No.60007 (4498) “Sir Nigel Gresley.
The jig for setting up the crank axles has been fitted to the newly-arrived return cranks.
Dummy cranks are being used as patterns for the machining work, which will start soon. Further components of the valve gearing have been cleaned and reassembled, such as the reverser column crank, lifting arms and radius rods, with work due to start on combination levers.
The contractors who will cast the new big end bearing have found an issue with the pattern, which they will need to modified to ensure the new cast has enough material to machine.
Pins, which hold the brake hangers in place, will be replaced due to excessive wear. The wear on the pins might be the cause of some of the brake hangers having small twists, which are hopefully within measurement allowances.
The superheater header has been fixed into position and hydraulically tested at the Llangollen Railway. Passing the test, the elements can now return to inside the smokebox. Operating gear for the ‘cod’s mouth’ door (the door in the streamline cladding to allow access to the smokebox in service) is now being inspected for any necessary repairs.
Alignment issues with the tender’s tank top have caused the door for the corridor to not close fully. The team has adjusted and added further jacks, both underneath and inside to ensure the tank top sits square.
Following this work, templates for replacement plates and supports had to be redone. Needle-gunning has been carried out to remove the majority of the corrosion on plate work. Work to the front end won’t be fixed permanently until the tank top is back on the frame.
Black gloss paint has been applied to the frame, with work progressing on getting the frame back onto its wheels. Most of the spring hangers are complete, bar one which failed it’s final Non-Destructive Test (NDT) and will be repaired shortly. The Hornstay bolts have been completed including hole for the split pin, and the brasses are being scraped onto the journals.
For more information or to support The Sir Nigel Gresley Locomotive Trust Ltd in overhauling their A4, please visit their website here.