BRIDGE 34 –GOTHERINGTON - 2nd REPORT ON REPAIRS
Repair works on this bridge are progressing well,
although the discovery of more rotten steelwork, combined with frequent
prolonged rains alternating with low temperatures make the work very difficult.
 |
| General view showing deck repair, drip strips and improved padstone support |
The amount of welding work required has expanded from
an original estimated 7 man days to a now most likely 40 man days!! Fortunately
we now have 3 excellent men who are working in very difficult conditions and
were there all of last weekend.
Temporary covers are being used ....
 |
| Squeezing underneath |
... but much of the work is below deck where access is very awkward.
As mentioned before a number of track bearer and cross
beam ends have been eaten away and the scale and rust has first to be blasted
away and then the rot left is cut away, back to good thick steel. Then new
pieces of steel can be installed and welded into place.
 |
| Corrosion identified |
 |
| Track bearer repair and drip plate added. |
Fortunately the 3 main girders have not suffered to
the same extent, but some stiffeners have rotted and have now been replaced
(see before and after photos below).
 |
| Corroded stiffener |
 |
| Repaired stiffener |
27 smallish pieces of plate have been welded to the
deck to cover the many holed and thin areas.
We had only estimated
that about 6 would be required from what could be seen from below!
 |
| Drip plates fitted to the edges to stop the water running back underneath. |
The rotting is
caused by surface tension where the water running off them instead runs back
underneath to the nearest cross member. We have now added a vertical drip plate
along the edges.
We have seen how effective this is with all the
rain that we have had. It also stiffens up the edge of the plates, reducing
flexing under moving loads.
All work below the deck, the deck plate repairs and
the drip strip are now completed.
 |
| Welding on vertical ballast plates |
All that is now left is to complete the
welding of the vertical ballast plates.
We expect that to be
completed by Friday 2nd Feb. Then the deck can be lightly blast
cleaned and the new waterproofing applied.
The work of grouting to fill the spaces beneath end
bearing plates is in progress, but another setback arose with 4 of these where,
many years ago (BR days), the original stone blocks had been cut back and new
concrete padstones had been installed.
Unfortunately all of these had been made
too small and some of the old stone left behind. This was breaking up, but worse,
the steel hung over the ends (see photos) and was not fully supported.
The loose stone
remnants have now been dug out and new thicker concrete padstone filling is
being installed.
The final coats of paint are being applied to the steel
the below deck and then bricklayers will be starting to rebuild the end ballast
retaining walls on Thursday.
The painters are having a few issues with low
temperatures and damp conditions, but are steadily progressing.
Report and pictures by:
John Balderstone,
GWSR Structures Engineer
Brilliant! Fascinating too.
ReplyDeleteregards
Colin
When I did bedstone repairs, the whole of the original stone was removed while jacking up the girder. A steel girder grillage was installed to take the weight of the girder end under load and then the whole thing was concreted in.
ReplyDeleteYes it was a bit of a surprise to find the fragmented stone remnants, but more surprising was that the new concrete padstones did not extend far enough and left most of the cross and track bearer girder ends unsupported! I cannot imagine how they could have accepted that, albeit the girders were fairly short.
ReplyDeleteJohn, that must have been a surprise. Over the years, I found that trial holes are a good idea, they can minimise the "Oh bugger, what do we do now" moments at the start of a night possession.
DeleteGood to see the bridges blog back on the main site, thanks! Will the bridge be back into use for the opening of the season? Looks like you had quite a lot more work to do than you imagined when you started! Good though to see such a high standard of work being done and very interesting to see the work in progress through the pictures and the words. Well done the bridge team, thanks for your efforts, always shows the supporters what's being done outside of the train rides to keep them running.
ReplyDeleteRegards
Paul & Marion
Thank you very much for a very interesting blog update. I recall, not long after joining the GWSR, there was much concern over the situation with another skew bridge - the one north of Toddington near Stanton - which had a leaking water main going through it. I think it concentrated our minds then just what a civil engineering curse we'd inherited. That said, many of the structures were, and still are, in very good nick! I agree with Paul S' comments above: but I don't think you should ask the question about whether the bridge will be back in use for the opening of the season in March (well, before I guess with the Gold Cup trains in mid-March perhaps?) because the answer may not be to one's liking!
ReplyDeleteYes,
DeleteVery well done so far. You're doing brilliantly. When I saw the photos which exposed the true extent of the decay, I thought , well, these men are not slow to accept a challenge ! I can see there's a lot to do, and in appalling weather, and there has at some time in the past been some very inferior repair work, particularly with the padstones. No self respecting engineer could approve that sort of work. But you seem to be very much on top of things !
(Yes, I know it's cold and wet. I hope you get some decent weather, soon. )
Good luck with everything.
Peter
Thanks for the interest and comments. Just to say that another update will be out shortly and that progress has picked up after a few dry days. We have every expectation that the work will all be completed by 27th February and P-Way will come in on 28th to put the track back.
ReplyDeleteOnly if BR had done the job properly in the first place, could it have been dangerous. There has been other shoddy work done in the past on the railway, unlike the very high standard you do it now. A very big thank you from all members and supporters
ReplyDelete