Two Hedges bridge

Two Hedges bridge - strange name, but it's just south of the former Bishops Cleeve station site -

and if you look carefully you can see a white building in the distance that stands on the old goods yard once next to the station. It was recently converted to a nursery. This picture then is looking north.

Two Hedges bridge is an over rail type and is basically constructed from 6 riveted steel plate girders resting on padstones, on Blue Engineering brick abutments. Between each of the steel girders there are brick arches (referred to as Jack arches). These are only 4 ½” thick laid as a brick on edge. The bricks are then covered with a concrete topping to form a level deck. The concrete is a minimum of approximately 2” thick over the crown of the arch, and it increases to approximately 12” thick at the deepest part where it touches the steel girders. This concrete is then given a waterproof coating of what was originally supposed to be ¾” thick Asphalt, according to the copies of the 110 year old original drawing that we have for almost all of our bridges. The road construction is then laid on top of the waterproofing. 

 

The Jack arches cause a sideways thrust on the steelwork and to prevent them spreading apart, which would eventually lead to the brickwork failing and dropping between the girders, a series of 7/8” diameter tie bars was originally put in – 4 per bay. Unfortunately, due to the smoke and water from the steam, over many years, these bars slowly corrode away and break. 

At the last inspection this bridge had 10 of the original 20  tie rods either completely broken, or reduced in diameter to about 3/8” and so we needed to replace those 10.

 

Starting on 30^th October 2017, we had a line possession and then the contractors replaced these 10 bars - not as easy as it sounds and took almost two weeks for 2 men! The bars actually pass through the brickwork, which is extremely hard, so to do the change the brickwork had to be broken out around the tie bars, the bars inserted and tightened and then the brickwork made good.

This photograph shows part of two tie rods. The end section with a nut on,  being the original 7/8” diameter bar and the other more like 3/8” diameter!! Coroded down to only half, while road traffic has intensified, and steadily increased in weight. These bridges were built in the time of horses and carts.

 

Whilst we had possession of the line we took the opportunity to carry out pointing of the brickwork. The line had to be handed back for race trains on Friday 17^th November, but we just about managed a week of pointing, which enabled us to point both abutments and all 4 wing walls.

 

None of this is very exciting but is something which needs to be done. There is a lot of other work which needs doing, including steel repairs (the poor condition can be seen in a couple of the photos!), but unfortunately the Budget would not stretch that far.

Early next year we will start making good the damage from a bridge strike to the rail over road bridge at Broadway, while almost simultaneously a second project will be launched at Gotherington Skew bridge. Further updates of these will follow once we have some pictures.