As previously indicated the boiler has been the are of concern in recent years. Back in 2000 Blanche spent the season running on the Welsh Highland Railway between the Caernarfon and Dinas. Whilst there she developed a boiler defect in the form of crack in the weld securing the superheater flues to the tubeplate. This was going to be fixed at Dinas until one of the dome fixing studs sheared. A close look at the metal suggested that it had deteriorated and become crystalline. All the studs needed to be replaced. As they are secured below the boiler flange with a nut the saddle tank had to come off! Blanche returned to Boston Lodge for this and other boiler work to be done. The following pages chart the 18 weekends in succession the team worked to repair both problems and return her to traffic.
Dome Repairs
I forgot my camera the weekend we removed the saddle tank so these pictures only show the reassembly work done over Easter. Click on any image for a larger picture.
These view shows the new studs and nuts in place after some serious hammering and tightening. Fitting these took most of a morning.
Before blanking it off the regulator face was
inspected and found to have signs of erosion in the top right corner.
Before
fitting the dome the copper sealing ring was annealed and is seen hear modelled
by Jo
The
dome was lowered in to place and bolted down temporarily. The regulator is
blanked off for hydraulic testing of the boiler so the dome will have to be
removed to refit the regulator. Back to top
With the dome refitted the tank was rescued from
its use as a depository for Boston Lodge crap and lifted high enough for the
engine to be pushed underneath it. Literally insert engine here!
Blanche naked. About to be pushed under the tank.
At this point I went to drive a train and missed all the "fun" of
making it fit. By Friday evening the tank was back on.
As you might expect the tank came off a lot easier
than it went back on! Here Mr. Walsh is jer, jer jiggling it a bit (and swearing
quite a lot). Back to top
Boiler Repairs
With the bit that got broken whilst getting ready to mend the boiler fixed attention can now turn to fixing the boiler itself.
Blanche's boiler is old. In 2003 its ten year boiler certificate will expire. This will come as a big surprise to management despite happening exactly 10 years after Easter 1993 when the boiler passed its steam test. When this happens the boiler will, at the very least, need major work or more likely replacing.
This view of the smoke box tube plate shows clearly the missing
large flues in which the super heater elements normally sit. The smaller smoke
tubes at this end are expanded in to place.
This view in to the firebox shows the missing flues from this end
and the welded repairs to the tube plate. The failure was at this end. A crack
formed in the flue and migrated in to the tube plate.
In this closer view of the welded repairs it can be seen that the
holes are no longer round. That will have to be corrected before new tubes can
be fitted. This view also shows that the smoke tubes are welded in. They were
originally expanded in to place but leaked persistently. This is largely due to
the inner firebox being well passed its sell by date.
Back
to top
Time for a Gizmo!
As mentioned above the holes in the tube plate have got to be made round again. This calls for a gizmo to be invented.
The first thing required is to get an alignment on the hole to find the centre. The ring in the first picture needs a bit cutting away to clear the weld but is then a good fit in the hole. Next the outer ring is placed on the inner ring and picks up its alignment. The outer ring is clamped in place by a method still being devised. Once in place the inner ring is removed and the cutter guide bolted on.
The cutter can be turned in the guide and has an adjustable
cutting tip at one end.
With the unit assembled the knurled ring gives control of the
feed whilst the cutter is rotated to cut the holes back to round.
Sounds easy but in a confined space it is likely to be time consuming. Back to top
The gizmo will be an on going saga, follow this link to follow the story. May WP's
Other Stuff
Whilst we all want to see Blanche back in action the tubes aren't due to be delivered until sometime later this month (May). In some ways we won't mind if they're late as we are taking the opportunity to address several other jobs on the engine. With the tank back on she's back in the New Erecting Shop and on the jacks as required.
Whilst a Dinas Blanche developed a liking for catching out the unwary and changing from full reverse to full forward whilst your back was turned. To stop this the reverser has been rebuilt to take up all the wear.
The vacuum pipe has had a small hole in it for some time and here Jo is allegedly welding it up although at one point it was about ten time bigger than when he started
The lubrication on top of the firemans side valve chest was found
to be leaking so this is being rebuilt and refurbished. This is the before view
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