DECEMBER 2007 PROGRESS REPORT
D1516's rocker gear has been removed from storage, and is being deep-cleaned prior to being checked for wear. Assuming wear is within tolerance these will be reunited with the power unit shortly.
The other good news is that the Project can now muster a passed loco
driver once again, which will allow much more operational flexibility
and will hopefully lead to greater use of 401 in 2008. Congratulations
to Project Engineer Richard Ward on being officially passed out as a
driver at the MRB.
D1516 PROGRESS - OCTOBER/NOVEMBER 2007
number of useful days (those without biblical rain/flooding and more
than three hours light) becomes less, the final push has been made to
get the power unit reassembly of 417 completed. The
cylinder heads have been refitted, and once reunited with the block,
the heads were aligned using the air manifolds as a jig, and were
torqued down. Sadly one of the manifolds was found to be cracked around a weld.
Dye penetrant was used to identify the course and root of the crack, then the damaged material was gouged out. Though the weld had started the crack, it had then propagated into the material of the main tube, the crack itself running at 30 degrees relative to the cross section of the material. As
the manifold had already been used to align the heads, a substantial
jig was made to retain the face alignment of the manifold before MIG
welding it up. Shimming material was used to take up fine misalignments. Following welding the manifold was re-checked for cracks and has now been returned to the stores for cleaning and repainting.
following weekend was spent torqueing the heads down to the final
figure, damned hard work which produced some imaginative uses of the
English language (we thought BR Blue was a livery not a dialect). The
double ended torque multiplier was used (one ratchet plus attendant
body per end), necessary to pull the head down evenly, this process
proved taxing but again, was quite rapidly completed.
roof section ex-47756 that has been sitting on the ground absorbing
space has had some attention to the north side, having had the welding
on the other side completed. New drains have been installed and
re-plating undertaken where necessary. Following welding, rust
stabiliser will be injected into the cavities followed by chassis wax. This will then melt and roll down the loco in the summer heat. Still, it wont rot.
Elsewhere, as the operating season for this year has finally come to an end, 401 has been drained and ‘tarped up. The
close of a less high profile operating season than 2006, but still
successful, a particular highlight being the three day stint vice-steam
in August where she just got on with the job – as it should be.
SEPTEMBER 2007 UPDATE
First we must report the sad news that our good friend, Peter Wood has passed away after losing his battle with cancer. Always prepared to go out of his way for anyone, Peter and his ever present Alsatians will be greatly missed around the site.
assisted the Project in countless craning operations and many road
movements (such as the transfer of 417’s main generator to and from
D&M for overhaul) behind his immaculate ERF B series or beloved
Scammel Highwayman. All of this was done without Peter accepting a penny in return. A superb engineer, he was always prepared to offer friendly and useful advice. His professionalism, dry sense of humour, and general attitude as a gentleman earned much respect from all who knew him. Thanks for everything Peter.
to the locomotives, and still determined to have a complete power unit
by the close of 2007, an investigation was made of the main bearings,
with appropriate rectification work being done as we progressed.
those of you unfamiliar with this process, much arm aching and
expletive inducing work is required on each of the seven main bearings
(per crank) to extract the shells and replace them. Firstly, the counter weight must be removed to gain access to the bearing cap securing squares and wedges. The
bolts retaining said weight have been glued to their respective holes
by twenty odd years of oily sludge, which has been injected into every
available gap through the centrifuge action of the rotating crank. Extraction
is made using an impact wrench borrowed from the MRB’s workshops which
is more used to extracting bits of steam loco, and as such proved to be
slightly overkill for our needs! The main bearings must be extracted one at a time to prevent the crank settling and hindering replacement of the shells. Each
bearing has two shells, the lower retained in the power unit's frame
and the upper in a cap – which is removed vertically and then slid over
and out above the position normally absorbed by the balance weight. The
retention of the bearing caps is achieved by wedges which act against
the power unit frame and are tapped home using a well judged hammer
blow. The wedges feature serrations and the
locking squares (which are bolted to the bearing cap) have teeth which
correspond with these serrations and prevent the wedge from sliding out. The
bearing cap retains its shell with two dowels which are screwed into a
rebate in the mating edges of the bearings, primarily done to prevent
the bearings spinning. Extraction and replacement of the bearing shells is achieved by turning out each one using a specially machined “mushroom”. The
mushroom’s “stalk” (for want of a better word) sits in the oilway of
the crank, and the head pushes the shell out as the crank rotates.
examination, we found that A Bank was largely fine, with all six
“plain” main bearings requiring no more than “topping and tailing”
(exchanging the shell which receives the thrust of the combustion
stroke with its opposite number in the cap to even out wear), and the
thrust bearing requiring similar. However, B Bank
was a different story, the thrust bearing lacked both of its dowels,
which aside from meaning it was only the “nip” of the shells that was
keeping them in position would also reduce oil pressure, as oil would
flow straight out of the bearing into the sump. Also water ingress had started to corrode the crank journal, though thankfully this was recovered with lapping paper. Two newly machined dowels were provided by Ian Crampton of the MRB, and with two new thrust shells the bearing was reassembled. The
remaining bearings on this bank offered similar tales of woe, two
further missing dowels were discovered (only one per bearing in these
cases) and three of the bearing caps were found to have worryingly
loose wedges. Four further bearing shells were exchanged for new ones to finish off 417's main bearings.
on the two locos over the summer period has included a start on
replacing the air filters and air filter housings on 47401 after one of
the housings fell to pieces during the loco's last running day on 16th
June 2007 (the running day otherwise passed without incident). Also,
several old contactors in the cubicle have been pre-emptively replaced
with nice new ones salvaged from the Class 455 refurbishment program!
to the running day 47401 worked several light engine test runs on 13th
June and also engaged in a bit of shunting of some of the Freightliner
flats that were at Swanwick Junction for overhaul. The first
'Generator' to work a Freightliner for quite some time....
selection of new piston rings were purchased for D1516 and have been
fitted to replace several worn and/or broken examples on the loco's
pistons. The overhauled pistons from 'B' bank were craned back in on
14th July 2007, followed by those for 'A' bank on 4th August 2007.