Tuesday, 27 November 2012

The disassembly continues: Bearings, Axles and Wheels.

Having removed the wheelsets from the frames, it's time to have a look at the state of the bearings, axles, and wheels.  Hold your breath!

The axleboxes are in two parts, both iron castings. The upper section holds the brass bearing and the lower, two fabric wipers that apply lubrication to the axle and retain any grit particles. Avonside had a simple and elegant method of securing the castings together: two steel pins (with a slight interference fit) pass through them and they are easily tapped out. 

We separated the axleboxes with some trepidation as we'd already found notable scoring on the valve gear's brass bearings, which means they will have to be re-made. We needn't have worried - both the axles and their bearings are in excellent condition and require very little work to bring them into first class condition. Unlike most British lines, The Royal Arsenal Railway had an abhorrence of whitemetal in bearings and none is present in 'Woolwich' although the 'slippers' on the sides of the axles boxes are whitemetal. These look good, but at the time of writing haven't been measured to ascertain whether replacement is required.

Whilst the bearing's condition is heartening, the rear right hand axlebox castings had a nasty surprise for us. We noticed that the securing pins were missing from one side yet the lower section was stuck fast in the upper. After much elbow grease it was discovered that the upper casting had been badly damaged, perhaps by dropping it during an overhaul. The missing metal had been replaced by stainless steel weld metal, built up to approximately the correct shape and then roughly filed down. The lower casting had then been forced into the other to give a very tight fit. This is probably the worst damage we've encountered and as you'll see, repairs are now underway.

Take a glance at our close-up photos of all the parts cleaned up.

Thursday, 8 November 2012

Removal Day.

The renovation of Woolwich goes on relentlessly and this update marks one year of our labours.  Will it end? Yes it will, in 2013, when we'll see the fruits of our labours.  For now, it's time to lift the mainframes to allow the wheels and axle-boxes to be withdrawn. The frames are in really very good condition. They are straight and the only corrosion is surface rust on a stiffening plate beneath the smokebox.

Rather than bring in a crane we decided to do the job 'in house' using lifting gantries with blocks and tackle. Once all the equipment had been checked for safety a larger than usual group assembled to remove the last components from the frames in the morning and conduct the lift in the afternoon.

The frames were lifted twice; firstly just the front end to remove the brake rodding and secondly to withdraw the wheelsets. A curious feature of the locos design is that it's impossible to dismantle the brake rods without removing their entire assembly. Removing said assembly is equally impossible unless Woolwich is either over an inspection pit or raised. No wonder the accident damage they've incurred has never been repaired.

Peter Letchford and Richard Seager took charge of the lift as both have a great deal of relevant professional experience. Not surprisingly they did a great job, with the heavy frames so perfectly suspended that a ball bearing would not roll if placed on them. The wheelsets didn't bind at all and once they'd rolled out the operation was completed by gently lowering the mainframes onto wooden blocks.

A most useful day's work that introduced the gantries to our arsenal of equipment. Many thanks to Kew Bridge Steam Museum for supplying them to Crossness.