|Introduction||Frame shotblasting||Wheel tyre turning||Tender tank||Rear Frame Stretcher||Loco rear dragbox|
The rear frame stretcher - January 2009
During the dismantling of the loco and the establishment of the required refurbishment of the various components it was assessed that the rear frame stretcher was quite wasted in places. It sits under the ashpan and so is in quite a corrosive environment. This together with the nature of its design leads to a number of pace where water can collect after damping down of the ashpan.
The plan it remove the stretcher and to have it refurbished at Brunswick Engineering in Caernarfon. They will conduct the work as they have effort available. This fits in with work on the rest of the loco as we will not need it for a couple of years.
Brunswick's built a jig in which to hold the unit whilst wastage was repaired. This it is hoped will minimise the distortion of the casting.
Progress to January 2011
Once the stretcher was removed from the jig it was apparent some distortion had taken place and this was visible when the stretcher was returned from Brunswick's for a trial fitting.
Once the full extent was established the stretcher was returned to Brunswick's for further attention and building up, especially on the faces that that mate with the frames, so as they can be machined to the correct angles again.
Progress to November 2011
Following final work at Brunswick Engineering the stretcher was sent to Boston Lodge for machining. This included the faces to the frame and the hole for the Krauss-Helmholtz truck pivot pin.
The rear frame stretcher in the machine shop at Boston Lodge.
Once this is complete we'll be in a position to refit the stretcher to the frames and then the rear drag-box can be removed for replacement.
In January 2012 the
frame stretcher was temporally bolted back into the engine
frames with just a few bolts on each side. During the January 2012
party all the temporary bolts were fitted and it will stay like this
whilst the rear drag-box is removed and replaced. Once the latter is
complete then both it and the stretcher will have their holes reamed
and then have 'fitted' bolts inserted.
The rear frame stretcher in its final resting place although yet to be fastened with the fully fitted bolts.
Once fitted the stretcher was painted in primer in order to keep rust at bay.
The rear frame stretcher having fitted bolts attached left and a view of the newly machined bolts right.
In May 2013 the rear frame stretcher was finally securred in place by Andy Bird from Boston Lodge using fitted bolts. The holes were first reamed out so as to be square and an accurate diameter hole. The bolts were then machined in the workshop to a very fine tollerance so as to ba very fine fit into the holes. Once bolted in place they will be just as effective as the original rivets.
By the June working party all the fitted bolts were in place.