This month we look at a small private bridge across the Tamar in North Devon and Cornwall.

One of the big differences between bridges and buildings has always been the need to build a temporary bridge to carry the permanent one while it is built. These bridges must be fiercely engineered for economy, but they are rarely recorded and leave little in the way of archaeology. Luckily, the engineers were often rightly proud of their centring and there are a number of volumes containing etched images of drawings.

This is claimed to be the biggest brick viaduct in the world. No doubt there are many other claimants to that title but few can be so impressive. It is, after all, 78m high, 574m long and 26 million bricks. I have wanted to see it for years and thanks are due to Stephanie Franck of HTWK Leipzig for taking me. We even got a balloon ride to get an aerial photo.

The bridge has actually gone, of course, and there is no record in the test report of where it was. However, there are some photographs, some graphs and some error strewn reporting in BA16 and nearly 30 years down the line it is time the record was straightened out while there is still someone able to do it.

I was introduced to this by Brian Duguid. The old Central Station, sometime GMex is built on a field of vaults which stretch to the canal. One interesting feature is the turntable just below the main sweep of the lines. It was deemed too heavy for the vaults and has a solid pier beneath.

Just a simple railway viaduct but with a very interesting issue. Had I not seen a version of this elsewhere, I would not have noticed. Looking from the north we see a stone built viaduct of no great height or pretension, though it is nicely done. I am interested in that patch of bright fresh stonework. Has there been a derailment?

Calstock viaduct is late as railways go (built around 1907) and unusual in that it is built of precast concrete blocks.

New is an interesting title for a bridge recorded as built in 1520, but new it is in the sense that there was an older one. The bridge is one of several of similar form across the Tamar, so from Devon to Cornwall. Until Brunel’s Bridge at Saltash it was the lowest bridge across the Tamar.

Do disused viaducts count? This one has a lot to offer in the way of strange details. Years ago, Tavistock was served by two independent railways. The Great Western came along the valley floor in
1859 and the Southern (well, strictly the Plymouth, Devonport and South Western Junction Railway) arrived in 1890, high above the town to the north.

This bridge is part of the highway system built by General George Wade after the 1715 rebellion. Before that there were no roads north of Perth. It is somewhat unusual in that we have the original contract.

Moor street station was built in the early 1900s as a terminus serving commuter lines into Birmingham from Leamington and Warwick. It is built on the side of a hill and though the station entrance is at ground level, the tracks are elevated on a blue brick viaduct. The space beneath was occupied by goods facilities with traversers and lifts. The piers of the viaduct have large arches to deliver clear space. That space is now a car park, and therefore readily accessible.

The Causey Arch was built in 1725-7. It has reasonable claims to being the first railway bridge in the world and for 30 years was the longest single span in the UK at 105ft (OK 32m). The mason was Ralph Wood. It was eventually passed by the new Bridge at Pontipridd by William Edwards.

This bridge, over Pinhoe Road in Exeter carries the branch line from Exeter to Exmouth. The single track is slightly more skewed than he bridge itself. It illustrates the ability to measure such things as skew from publicly available data.

Pictures of this bridge were given to me some years ago and I couldn’t place them. (Shortly after this was published I received an email from Jose Martin Caro to say that the bridge is between Venta de Baños and Burgos in Spain.) The main reason for putting it here is the clues it gives to construction.

Several early railways to Kent run south east from near London Bridge Station on viaducts and the combined viaducts are beginning to spread. They are, of course, independent, though where they abut one another the construction may vary.

This month we will return to the Exe bridge as an example and think about the implications of pointed ribbed arches when it comes to assessment.

Leaths Bridge is just to the East of Castle Douglas in SW Scotland. Long disused, it used to carry the A745 over the railway but the railway was closed and the alignment taken over for realignment of the road. The bridge was left in a loop and totally neglected for many years.

Hubberholme is a joyous memory from student days, right at the top of Langstrothdale. It is famous for its church but for us, the bridge is more significant. This general style of construction is not particularly common.

Balcombe Viaduct on the London‐Brighton line is a magnificent structure, so much so that it shows clearly on Google satelite photographs and in streetview. That it is magnificent is enough to make it worth consideration, but there is room for a little more thought about what has been done here both in an engineering and an architectural sense.

Bridgemill no longer exists. It stood on the A77 near Girvan and was tested, notionally to destruction, in 1984. The test has been used as part of the justification for a number of non‐sensical statements about arch bridge behaviour.