A viaduct special:

Stanway Viaduct - Bridge 12

As we now have a bridges blog, we thought our readers might be interested in work on a much bigger bridge - Stanway viaduct. This structure in engineering blues has 15 arches, is 210 yds long and spans a small stream at a height of 42ft. It's not only built on a curve, but also has a falling 1 in 150 gradient towards Toddington. Complicated ! You have to admire those Victorian brick layers. Nonetheless it was built in only 16 months... maybe a bit too fast, as 3 arches collapsed, one by one, while it was being built in 1904. The Achilles heel was not the design nor the terrain, but the fact that the supporting wooden supports underneath the arches were removed too soon, and then a heavy 14ton crane was rolled on top of the new brickwork.

Well, the viaduct has now been up for 110 years, and it has a vital place in our bridge maintenance programme. As with a number of other bridges on the railway already (most recently, J.J. Farms bridge) we do maintain our structures (not just the ones on the new sections!), and Stanway Viaduct features large upon it. As you can see in the opening picture, ivy started to creep up it, and force its way into the brickwork.

Time to do something about this! In the picture above, a section of ivy has been removed for inspection, and you can see the damage caused by this invasive plant.

The affected piers were then surrounded by scaffolding, the ivy removed and the damage made good with new bricks and mortar.

You can see in this picture how deep we went in order to get to unaffected, solid brickwork. We used original Victorian imperial blues, so that the same strength and looks are achieved:

You can't tell the difference between old and new. We even found the correct bull nosed corner bricks. That pile underneath by the way is not old bricks, but mangel wurzels for sheep feed. We didn't take out that much. In order to further strengthen the repair, stainless steel Cintek anchor bars were used in the repairs. As blue bricks don't absorb mortar very well, we only inserted a few bricks at a time, moving on to a different repair until the mortar had gone off on the first.

As the scaffolding was already up, we also refreshed some of the brickwork higher up in the arches:

A small amount of 'nibbled' bricks remain at ground level, and these will be done by a crew without scaffolding at a convenient time later.