Wednesday, 24 May 2017

Component preparation

Photos by Rob Bishop & Emily High

Three views capturing some of the bits that have recently been grit blasted, which provide a flavour for activities later this year.

The big bits in the foreground of this image  include the (from right to left), the covers for the cam shaft/ valve push rods and the gear train from the MDB4 engine (see photo below), followed by the cover for the gear wheel on the lay shaft, which forms part of the final drive and the casting which carries the starting mechanism (see 8th March 2017 update)

This is the final drive from the gear box to the lay shaft, which is protected by the cover in the centre of the first image. The ‘shadow’ of the cover can be seen. The upper strap of the transmission brake is also visible in this view.

The large wheel on the left of the view  is the drum for the transmission brake. Other transmission brake components on view include the two crescent shaped plates (centre) and the brake shoes (rear), see 8th March 2017 update for the relationship of the transmission brake bits. The other components visible include the drive pulley for the water pump/ fan belt, a cab stanchion, parts from the lay shaft and the engine starting mechanism.

An easy one to spot. The cab rear sheet, complete with drivers’ seat.

Sunday, 21 May 2017

Turning the wheels

Photos by Rob Bishop

A short and sweet report.

The picture of Rhys Hughes below says it all - the wheels for KS4415 are being turned and the journals skimmed...

The frames turned over

Photos by Rob Bishop

After two years lying on their back, the frames have now been turned over and are now the right way up, so here are a few general views to place the various components into context. This photo from the rear of the loco shows the sub-frames in position, with the spring pockets bolted on and also the brackets for the brake gear fitted to the underside of the floor. The brake weigh shaft is to the left, under the cab floor and the angles which will carry the drag box can be seen behind the front buffer beam. Dave Hatt is about to put in a cameo appearance to rivet in the upper drag box angles.

This view from the front clearly shows the welded in repair to the rear frame stretcher (bottom)

Frames right side up:

                                                      July 2015
April 2017

Engine Mounts

Contrasting views of the engine mounts before and after:
The semi-circular mount was for the dynamo. The heavily rusted cab floor plate was originally riveted in. The replacement will be fitted with set screws to allow access to the dragbox for maintenance. 

While the upper surface of the floor is heavily pitted, it is still fit for purpose and has been retained, in line with the conservation ethos of the project.

Friday, 19 May 2017

The Brake Linkage

Photos by Rob Bishop

The next few photos of odd bits of bar will make a lot more sense if you understand how the brake gear works. The pull rods act on two suspension arms, on the centreline of the loco. The suspension arms act in turn on two short links which pull on the carrying arms which carry the brake blocks. The carrying arms are themselves hung from two suspension links, all coloured luminous green in the section below.

These are the brackets for the suspension links. Central bracket for the pull rod link, outer brackets for the carrying arm.

The rear assembly. This pivots from the frame via the top hole, with the pull rod acting on the bottom hole. The brake block bolts to the outer hole on the carrying arm while the inner hole is for a clevis to carry the suspension arm. The carrying arms are shaped to clear the flanges.

The carrying arms, fitted with clevises for the suspension arms. Note the rather crude flame cut finish.

Both carrying arms complete with suspension links.

The suspension links fitted to the frames. This is the front unit. The bracket on the central link is for a release spring, which connects via a hook to the hole in frames. This spring pulls the brakes off the wheels when they are released.

Thursday, 18 May 2017

Drag Boxes

Photos by Rob Bishop

The lack of recent news does not reflect a lack of recent progress. This report focuses on ‘new’ construction. KS4415 has never had a ‘drag box’ per se, merely couplings and buffers attached to the buffer beam. In early 1929,  KS4415 was fitted with chopper couplings to allow it to be used on passenger trains on the WHR. This is the period the restoration aims to represent. How the chopper couplings were fitted is unclear. Getting the coupling arrangement right is essential for the safe operation of the locomotive so we are shamelessly adopting current technology. To provide an idea about what we are currently fitting, here is ‘the answer’, in this case fitted to new FfR observation car 152.

Dragbox Assembly Car 152
The drawbar pivots in a crosshead. The crosshead is supported on two large bolts, with a series of rubber pads providing springing for both haulage and buffing loads. On KS4415 space to install this arrangement is limited, so rather than being fixed to a frame stretcher the dragbox assembly will be fixed to a strengthened buffer beam.

One of the crossheads for KS4415

The bufferbeam marked out for the new slot
to accommodate the coupling

Spare’ holes welded up, and new slot cut

A doubling plate has been fitted inside the frames

Having welded the old holes up Matty Wolstenholme drills
 a new row of holes. These will be used to rivet a pair of angles
 inside the frames which will carry the dragbox.

New holes, meet old holes

The angles used to fit the drag boxes to the frames
have been riveted in. The two bars labelled ‘top’ and ‘bottom’
are the start of the dragbox and are bolted to the angles.

The rear unit is more bijou.

Friday, 10 March 2017

Update 8th March 2017

Photos by Rob Bishop

In the last update the transmission brake received a mention. Despite looking quite fossilised, it stripped down nicely and all of the components are reusable.
Transmission brake dismantled

The subframes have now been fitted and the grey top coat applied. This view looking to the rear of the frames clearly shows the rear frame stretcher repair and also the repaired areas of the sub frame.
Subframes looking back

This is the view looking forward, showing more of the sub frame repairs and the various brackets which carry the brake gear, with the slot and cut away section of the frame where the transmission chain from the lay shaft comes back onto the leading axle.
Subframes looking forward

Assuming that you are interested in watching paint dry, here is an overall view of the chassis. The 1 ½” hole in the frames at 5 o’clock to the large layshaft bearing hole is to take the ¾” bore pipe which connects the exhauster to the train pipe. 
Chassis side view

The ‘T' which protrudes through this hole, can be just seen in this 1929 view (now located at 11 o'clock to the layshaft), with a witness streak ‘crying’ from it .
1929 view

This interesting assembly came with the MDB4 engine from Armley Mills and is part of the starting mechanism, which is located in the cab below the radiator. I’m struggling to recall how it all works, the upper shaft (with the square end) is in line with the Diesel engine crank shaft, while the lower shaft is connected (via a chain drive) to the Blackburne donkey engine. If you put the starting handle on the upper shaft you can turn over the Diesel engine, but by disengaging a dog clutch you can use the same handle to start the donkey engine. The outer rim of the lower gear wheel is part of a band brake; the strap for which is in situ below the wheel. When this brake is applied, via a small handle (missing, but pivoting in the bracket bottom left) the drive from the Donkey engine can then be used to turn over the Diesel. I’m aware that I have missed something out here, it will all become clear in another thrilling instalment.
Starting mechanism

Getting back to a specialism we all understand, here is more paint drying, this time on the axle boxes & handbrake stanchion.
Axle boxes and stanchion newly painted

Thursday, 26 January 2017

A Removable Panel

Drawing, by Kerr Stuart, Photos by Emily High and Rob Bishop

We have, at long last reached the end of the frame repairs. At some stage in the past a section of the front, drivers side frame was made removable, possibly by Hunslets before the loco went to Mauritius. The Kerr Stuart frame drawing has a note ‘see HECo’s (Hunslet Engineering Co) drg No 30931 for alts to frames of L4415’. We don’t have a copy of that drawing, but the frames do not appear to have received any other modifications. The removable panel can be seen in the photo below, with the lay shaft bearing central in the panel. 

When you see what is behind the panel, the benefits of making it removable can be appreciated.

The photograph above is taken looking down into the frames from the front buffer beam, driver's side and shows the components located on the layshaft. From left to right can be seen the gear box, the front longitudinal frame stretcher, the spur gears taking the drive from the gear box to the lay shaft, the lay shaft chain sprocket (note the chain shaped wear on the hole in the stretcher behind) and the transmission band brake. All of this is contained behind the removable frame, and given that the sleeve which contains the lay shaft extends for the full width of the loco, getting at these components without the removable panel must be a nightmare.

So, non-original it may be, but retention is the way forward.

This is the frame extension, with the holes being tidied up on the radial arm drill.

The holes have been modified to take plough bolts; these have a counter sunk head, 
but a square on the shank to stop them turning when they are being tightened.

The frames with the removable plate re-fitted

Before the frame was re-fitted an opportunity was taken to ream out the bracket 
for the transmission brake and fit a new pin. 
The chains did nibble a good bit out of the frames (top right)! 
It is interesting that the opening in the frames have been flame cut