Friday, 23 September 2016

Update on bridges 1 and 45

It's been a while since we posted an update on the bridges, but we haven't gone away. We continue to monitor all of our many charges, and repair them where work that needs doing is selected for action.

BRIDGE 1 – STATION ROAD, BROADWAY

As you may know, bridge 1 at Broadway has been hit a number of times since it was repaired 2 years ago, at least 5 times and possibly even more. 3 of the vehicles involved were skip lorries - local ones at that - and two were curtain siders. Those are the ones we definitely know of. All forced themselves under the bridge, and out the other side, leaving a trail of ripped off bolts, ruined paintwork and torn electrical conduits.

Work started on 19th September 2016, to repair the effects of the several bridge strikes, and while the team was there, to point up some damage to the wing walls as well. The basic tasks are :-
 
1.     Carry out an inspection by a Professional Engineer, working from a lorry mounted cherry picker to determine whether any serious damage had been caused. Verbal indications today are that there is none.


Bridge inspection by engineers
 2.     Raise the conduits and cables that supply power to the low headroom warning signs. The cables have been sheared off on 4 occasions despite being higher that the headroom height stated. 
 
Moving the electrical conduit
3.     Replace approximately 6 bolts and one rivet that had been sheared off.
4.     Clean and paint approximately 200 rivet and bolt heads and numerous parts of the steel structure, which had had the paintwork scraped off by the various lorry strikes. 

Paintwork repair by the Broadway gang
In addition we are taking advantage of the partial road closures to undertake the pointing of sections of wing walls, which we couldn’t afford to do when the bridge was refurbished, 2 ½ years ago. 

Wing wall repointing work

A view of the work from the Evesham side
Next week full height scaffolding will be put in place to give access the high level brickwork on the downside, Cheltenham end. We are fortunate in that the nature of the work permits us to do the repairs one side at a time.

BRIDGE 45 – SWINDON LANE, CHELTENHAM

At the other end of the line, our regular inspections of all our structures has revealed that work now needs doing to Swindon Lane bridge.
This bridge, number 45, is located south of Hunting Butts tunnel, where Swindon Lane crosses the line as it enters a cutting. At the other end of this cutting, the trackbed begins to touch Pittville Park, and that is the end of the actual trackbed that we own. Even though we don't run any trains down this last stretch of under a mile, we continue to be responsible for the bridges.

Swindon Lane bridge looking south
A very small but vital task was carried out on this bridge last week. The bridge is constructed from 6 main steel girders running parallel with the road, and between these the gaps are filled with long panels of Jack arch brickwork. This brickwork is then covered with concrete to form a level surface, which is waterproofed with asphalt before the road materials are laid on top. The arch brickwork naturally has a sidewards thrust, which tends to push the main girders apart. This is prevented by the use of horizontal tie bars which link them all together. Unfortunately 4 of these tie bars had corroded right through and were missing, and another 3 had reduced from 7/8” diameter to less than ½” diameter. 

Arches held in place by girders tied together
 




The work required was to replace the missing ones and also remove and replace the downgraded ones.
 






Cut out for a new tie bar



Several of these passed through the very tough Jack arch brickwork, which had to be cut out and made good.

Corrosion on the girders themselves is also evident.






New tie bar inserted






A cherry picker was hired in to survey and repair the corrosion.

The cherry picker enabled Alastair Watson (of drainage gang fame) to take these pictures for us.










New tie bar in place.


Finally, a picture of the bridge looking north towards Hunting Butts and CRC. The concrete bridge in front carries the footpath, as the original bridge is on the narrow side and carries traffic far heavier than imagined in 1906.
There is a weight restriction on it.

If you are interested in this piece of our trackbed, you can see more photographs of it here: