David Elliott and Mick Robinson had a successful weekend at Darlington Locomotive Works. The main frames now have the bends in them, and the remaining frame plates have been set up and temporarily bolted to the main frames.  The bends in the rear frames (needed to allow room for the Cartazzi wheelset to move sideways without the wheels hitting the frames) were achieved as follows:

A bending former was made up using a piece of steel plate normally used to the protect the inspectionpit boards from exceptionally heavy loads, to which was temporarily welded a hefty piece of rolled steel joist (RSJ) which forms part of the boiler cradle, a specially pressed former to provide the correct bend diameter and a spare piece of angle to brace the upright to the floor plate.  This was carefully lined up with the inside of the required bend and secured to the rails by large tack welds.

The rig is set up around the frames to start the bending process – David Elliott

The former around which the bending will take place – David Elliott

The area of the frame to be bent was then heated using two large oxy-propane torches, two being required to reach the necessary dull red heat in the whole of the width of the 30mm plate being bent. Two complete bottles of oxygen were used, made possible by the loan of a second oxy-propane set from M Machine.  The rear end of the frame was then formed into the correct place using the fork truck, the angle of the bend being checked with a laser profiled template CNC cut from the 3D model of the frames.

The first bend successfully completed – David Elliott

The rig re-set for the second bend – David Elliott

The completed bends – David Elliott

Mick Robinson warms up the next area to be bent – David Elliott

With the inner frames bent to shape, the Cartazzi frames could be bolted on – David Elliott

One of the frame joins and the threaded bolts securing the plates together – David Elliott

With the frames delivered, out came the frame stands last used for Tornado – Tony Lord

The frame plates were roughly positioned – Tony Lord

A close up of the doubler welded over the Cartazzi axle – Tony Lord

A view from the firebox end – Tony Lord

One side of the frames is uprighted – Tony Lord

The frames erected on the stands and held together with threaded rods – David Elliott

The opposite view from the rear of the frames – David Elliott

The Cartazzi frames and additional doublers awaiting fitting – David Elliott 

Prestons arrive with the frames from Boro’ Foundry – David Elliott

The wagon is carefully backed into Darlington Locomotive Works – David Elliott

The smaller front frames are craned off – David Elliott

The main frames then follow – David Elliott

The frames have landed! – David Elliott

Wasting no time, Dave Brown from North View Engineering welds a doubler on – David Elliott

The frames are uprighted to facilitate this – David Elliott

David Elliott delivered the Tornado patterns for pony, Cartazzi and tender wheels and the coupled hornblocks to Cooks at Sheffield at the start of July.  The first coupled wheel has already been cast and we will add photos as soon as it is broken out of the mould

Good progress is being made with preparing the expanded polystyrene patterns for casting with the addition of runners and risers.

The coupled wheel pattern is prepared for casting – David Elliott

The mould box containing the first driving wheel casting for No. 2007 – David Elliott

The substantial polystyrene pattern for the dragbox – David Elliott

The frame stay / boiler support pattern – David Elliott

The pony and Cartazzi wheel and coupled horn block patterns delivered to Cooks – David Elliott

These photos and the video show progress on the milling and drilling of the main frame plates at Boro’ Foundry at Stourbridge. The main frames are set up on the large Elga Mill and the top surfaces are being machined first. The table is big enough to accommodate the 11.2m length of the main frames, however the cutting head can only move 8m. Hence the frames will be reset 3 times, once to complete the machining of the top edges, then twice more to machine the bottom edges and the horn slots. Fortunately 8m is long enough to machine all the horn slots in one setting which will ensure that their positions relative to one another are accurate which will make eventual setting of axle centres easier than with Tornado.

The leading frame extensions are simultaneously being machined on a gantry mill. The left and right hand plates are tack welded and clamped together on the machine table so that they can be machined and drilled together. The video shows the cutter returning to the start of a cut at the rear end of the upper edge of the frames and proceeding via a large cut out where the one piece cylinder block will sit. All edges of the profiled frames are being machined to remove the metal that is heat affected by the flame cutting process. Typically 0.25″ is being removed around the edges in 2.5mm deep cuts. (Apologies for mixture of imperial and metric units – the drawings are imperial, the machine metric!). After the plates are accurately set up both machines, cutting is Computer Numerically Controlled (CNC) from a .dxf drawing which in turn is derived from the Solidworks 3D model of the locomotive.

The buffer beam and small components – David Elliott

The leading frame plate extensions are milled – David Elliott

A different view of the milling in progress – David Elliott

Machining the cut-outs for the cylinder block – David Elliott

Viewed from the rear, the sheer size of the frames is apparent – David Elliott

Milling the main frames – note the tack welds holding the two together – David Elliott

The tender frames were machined at the same time as the main frames – David Elliott