Scottish Bridges: 57. Abergeldie Castle Bridge (after the flood)

This is the third of three flood-damaged bridges that I visited on the River Dee in Aberdeenshire during August 2016.

When I visited in 2012, the bridge was derelict and had been so for some time. At the time, I said:

I’d be astonished if the deck is still there in ten year’s time, so if, like me, you have a soft spot for derelict bridges, I suggest you visit it while you still can.

That opportunity is now gone, as the bridge collapsed during the Christmas 2015 floods.

A video on YouTube makes clear why the bridge collapsed: the entire southern bank of the river was extensively scoured away by the flood (compare my 2012 photos to see quite how much has gone).

Survival of the adjacent Abergeldie Castle was clearly a far greater concern than the bridge. The bridge's southern tower and anchorages were simply swept away along with the rest of the river bank - you can still see a remnant of the main suspension cable anchors in one of my photographs.

This video shows some of the river bank protection works in progress during January 2016, as well as the remnants of the bridge;

It's a huge shame that this bridge has gone - it was of an unusual type with two suspension cables on each side, one above the other. I'm not sure how many other 4-cable suspension bridges there now are in the UK, if any.

The Abergeldie Castle bridge was originally built by Blaikie Brothers on the instructions of Queen Victoria, at roughly the same time as she authorised them to improve the Crathie bridge discussed in my previous post. A contemporary article on the building of the Abergeldie bridge can be found in The Engineer, 7th August 1885 (page 103), and I reproduce here the accompanying bridge plans:

While preparing this blog post, I also found a photograph of the 'bridge' which predated the suspension bridge. This was a cableway structure, used to transport mostly goods and the occasional person. It's what would nowadays be called a "bucket bridge", and there are precious few of these still in use (possibly just two in Scotland):

It was unfortunate that the local planning authority took no enforcement action on Abergeldie Castle bridge's owner to preserve the structure over a number of years as it was gradually allowed to deteriorate, but nothing could have saved it from the 2015 storm.

Anyway, here are some pictures of what remains of the Abergeldie Castle bridge. The bridge pylon from the south bank was swept downstream but remained attached to the north pier, so that almost all of the bridge's wreckage now rests on the north bank.

 

Scottish Bridges: 56. Crathie Suspension Bridge (after the flood)

This is the second of three damaged bridges that I visited on the River Dee in Scotland during August 2016.

Built in 1834 and modified in the 1880s, this is a remarkable and highly unusual bridge, with a bizarre set of hybrid structural supports both above and below the bridge deck. When I visited in 2012, it was in great condition.

Following the Christmas 2015 floods, the bridge has been declared unsafe and closed to users.

It doesn't appear that the bridge has suffered much damage. There is no change to the tie-back rods from what I saw in 2012.

One of the deck edge rods is loose, but this is not new.

The only significant damage I observed was where one of the deck edge rods is broken. This should be straightforward to repair.

I'd hope this bridge can be repaired and reopened without too much further delay, but as with the bridge at Cambus O'May, it doesn't provide any vital access, so it won't be a priority for the local authority.

Scottish Bridges: 55. Cambus O'May Bridge (after the flood)

A couple of weeks ago, I visited the River Dee in Aberdeenshire, and returned to three bridges which I had previously seen in the Summer of 2012.

At Christmas 2015, the Dee experienced one of the most severe floods in its history, along with several other rivers in Britain. A number of bridges along the river were severely damaged, and one destroyed.

Cambus O'May Bridge was built in 1905 by James Abernethy & Co., and then substantially rebuilt in 1988. It's a very fine pedestrian suspension bridge, one of many along the River Dee. It looked good on my 2012 visit.

It's amazing that the bridge survived the 2015 flood at all, as the level of water battering the bridge can be seen in the video below:

When I visited in mid-August 2016, the damage to the bridge is clear. Unsurprisingly, it is currently closed, with no sign of any plans for repair work.

The entire structure has been bent sideways by the force of the water.

Several of the bridge hangers are missing or bent.

Most significantly, there is major damage to one bay of the main deck lattice truss, presumably due to impact from debris.

I think the most likely future for this bridge is another reconstruction, as I think it would be inordinately difficult to cut out and replace the most damaged section and to straighten the remainder of the bridge. That seems unlikely to happen any time soon, as the bridge does not provide critical access to anyone, and I imagine there are other priorities for limited budgets.

Scottish Bridges: Final summary

At last, that's over. I started posting reports on the bridges visited during a 3-day Scottish tour at the beginning of July, and it has taken until now to finish covering them all. There were 35 bridges seen over those three days, and this map shows the ground covered (blue is the first day, red the second, and green the third):

I said at the outset that "Several of the bridges are among those in Britain which any serious Pontist should try and visit once in their life".

These are the ones I would recommend going out of your way to see, if you get a chance:

• Bracklinn Falls Footbridge
• Broomhill Bridge and Aultnaslanach Viaduct
• Findhorn Bridge
• Whin Park Bridge
• Craigmin Bridge
• Falls of Garbh Allt Bridge
• Kirkton of Glenisla Bridge
• Haugh of Drimmie Bridge
• Invermark Footbridge

I plan at some point to complete a similar tour of the western half of the Scottish highlands. In the mean time, now that this mammoth task of reporting on bridges is complete, I can get back to some more "normal" blogging. Next up, as soon as I get time, will be a series of book reviews.

Scottish Bridges: 54. Footbridge at Invermark

The grand finale. The pièce de résistance. This, believe it or not, was planned as the culmination of our entire Scottish bridge tour. And, I think, rightly so.

You won't find any information about this bridge online, indeed, so far as I can tell, the images I'm posting here are the first on the internet. It's in the middle of nowhere, across the River Esk, at the far end of the road in Glen Esk, close to Invermark Castle. It leads from a field across the river towards the hills, and I imagine is mainly there for the use of anglers. A sign at one end reads "Dalhousie Estates - Private estate bridge not for public use - any persons using the bridge do so at their own risk".

I first encountered this bridge through Mike Schlaich and Ursula Baus's excellent book, Footbridges, where it is accorded a two-page spread, ranking it up there along with some of the finest contemporary pedestrian bridges. Ever since then, I knew I had to see it for myself.

By the standards of some of the bridges to be found elsewhere in the world, this is a high-quality, sturdy structure. By contemporary British standards, it is a thrillingly ramshackle agglomeration of scrap metal and wood, the sort of thing you might imagine the man who repairs the fences on an upland farm throwing together. Which is precisely what seems to have been the case here.

The bridge appears to be held aloft largely by the power of wishful thinking. At first glance, you may note the presence of suspension wires at either side, and assume that these support the deck, but in fact these are merely there to hold the wire-mesh "parapets" in place. The bridge deck is of the catenary suspension form, comprising three timber planks, with occasional cross-planks, supported on precisely seven strained fencing wires. These provide the primary, possibly the only, means of support.

The support wires are braced via cross-members against the tree-trunk masts, which in turn are held back by stay wires, anchored into further timbers driven into the ground. Mesh-link fencing at either side of the approaches to the bridges steers the traveller towards the steps, and presumably serves the more important function of keeping livestock from pulling the wires down.

Lateral tie wires have been installed to reduce lateral sway, although even with these in place, this is possibly the most precarious bridge that I have ever crossed. It's hard to escape the feeling that you will be pitched into the river at any moment.

At one end of the bridge, the main deck support wires are wound round tensioning ratchets. At the other end, they are simply turned round a cross-bar and twisted together. This really is all that holds you up while you cross.

Everything about this bridge is brilliant. It's an adventure to use, a heart-punching antidote to the sanitised world of health-and-safety that binds most bridge designers. It's also a splendid example of the charms of vernacular design. Can anyone imagine a professional designer producing something so intriguingly crafted?

It provided a fine end to our trip.

Further information:

• Google maps
• Footbridges (Baus / Schlaich, 2008)

Scottish Bridges: 53. Loups Bridge

Loups Bridge is another of John Justice Jr's structures. We'd been to his other bridges at Crathie, Kirkton of Glenisla, and Haugh of Drimmie, and Loups Bridge completes the set: the only other Justice bridge known to survive.

Loups Bridge spans the River North Esk not far from Edzell. I guess it is named for the waterfall which cuts through a rocky channel just below it, "loups" referring to a salmon leap.

The bridge is on private land, and I'm not clear whether normal Scottish rights of access to walk across the land apply, as it is in the grounds of a partially residential building. The Happy Pontist had obtained permission from the landowner to visit the bridge on this occasion.

The bridge has two spans, supported by a masonry pier at its centre. The RCAHMS website lists the spans as 9m and 10m, but also states 15m and 17.4m, while Ruddock's paper lists two equal 36 foot spans. I don't know which is right.

The bridge is Listed Grade B, and seems of considerable historic importance as a rare example of the Justice family's work, and also as one of the earliest surviving stayed bridges in the UK. Its exact date of construction is unknown. It may possibly pre-date the stayed footbridge at Kirkton of Glenisla, which was built in 1824, or the Haugh of Drimmie bridge from 1823.

Unlike the other Justice bridges that we visited, Loups Bridge is derelict. Very little of it remains, and it would be foolhardy to try and walk across it. It is more than a ghost of a bridge, but only barely so.

From what can be seen, it's clear that the bridge's skeleton must have been exceptionally slender even by the standards of other Justice spans. The stay rods and cross-members are tiny in cross-section, and the odd arched pylons above the pier are not made out of anything more substantial. There are two wire-like stringers which must once have been below a timber deck, and I would guess there were once longitudinal edge members providing tension ties to the inclined stays. Most of what now remains would once have formed the wire-fence balustrades.

It would make for a very interesting restoration project, but I suspect this bridge is well past the point where it can be repaired.

Further information:

• Google maps / Bing maps
• RCAHMS
• British Listed Buildings
• Aberdeenshire SMR
• Some iron suspension bridges in Scotland 1816-1834 and their origins (Ruddock, The Structural Engineer, 2003)

Scottish Bridges: 52. Haugh of Drimmie Bridge

The final day of our Scottish bridges trip revolved around the bridges of the Justice family of blacksmiths, all built in the period from around 1820 to 1840. Five of their bridges are known to have been built, although the one at Clova Kirk in Glen Clova is long gone. Of the other four, we had already visited those at Crathie and Kirkton of Glenisla. The next bridge is in many ways the most accomplished of them all, at Haugh of Drimmie, near Blairgowrie.

This bridge spans about 32m across the River Ericht, and is 3.2m wide. It is Listed Category A. Its exact date of construction is not known but it was mentioned in the 1837 New Statistical Account of Scotland, with the following description:

"The only other object pertaining to this parish, which I shall mention as a matter of curiosity, is an iron bridge, which Colonel Chalmers of Glenericht, has thrown across the river, a little below his house. The bridge is supported by a stone pillar at each end, from which a direct span, not an arch, stretches across the whole breadth of the river. The bridge is of such wideness as to admit a passage for a carriage, with a foot tract on the side for travellers, the bottom or floor of both of which is covered with gravel to prevent alarm to man or beast. By this bridge, the Colonel has easy and elegant access to his property on both sides of the river, and also to the great road which runs from Braemar to Perth. The bridge was constructed by a Mr Justice in Dundee, and is well worth the notice of strangers."

While this hardly suffices to describe the bridge, it does offer a nice reminder of quite how compellingly strange it must have appeared when first built. In the 1820s and 1830s, a flat span bridge of any dimension was still a tremendous novelty. A few isolated suspension bridges had been built, but girder and truss bridges of any size were still to come.

The Haugh of Drimmie bridge has retained a definite strangeness today. Clearly, its deck has been altered over time, but the main structure seems to be original. It very closely resembles Justice's bridge at Crathie, with amazingly slender pylons, rod stays at a very shallow inclination, and a panoply of transverse and longitudinal bowstring ribs below the deck. Unlike its sibling, it was never strengthened with suspension chains, and also unlike its sibling, it continues to carry vehicles today, albeit with signs at each end declaring a weight limit of 2 tonnes. Given the extraordinary slenderness of many of its parts, particularly the pylon legs, I find this quite astonishing.

It lacks the rag-tag charm of the 1824 bridge at Kirkton of Glenisla, and was clearly a much more polished venture. Nonetheless, many individual features are essentially the same, such as the presence of curled ornamental brackets at the base of the pylon legs, the varied use of through-bolts and external clamps to connect the main span and anchorage rods to the pylons, and the presence of slender arched portals above the pylons.

The bridge deck is constructed in timber, with narrow timber "footways" which with their tall kerbs are an effective way of limiting the live load on the bridge. The kerbs also provide the primary vehicle containment, protecting the weak parapets as well as the hanger rods. Hidden below the deck there are scuppers at regular intervals which allow water to drain.

As with its sibling structures, it's only when you step back and consider quite how tiny the individual members are that you wonder quite how it has survived for so long. I think this is one of Scotland's finest historic bridges, and it deserves to be much better known.

Further information:

• Google maps / Bing maps
• RCAHMS
• Engineering Timelines
• British Listed Buildings
• New Statistical Account of Scotland, Vol. 10 (1837)
• Scottish Suspension Bridges (Hume, Scottish Archaeological Forum Vol. 7, 1977)
• The 19th century iron bridges of Northeast Scotland (Day, Journal of the Society for Industrial Archaeology, 1998)
• Some iron suspension bridges in Scotland 1816-1834 and their origins (Ruddock, The Structural Engineer, 2003)

Updated 27 September 2012:

See the comments on this post for some very interesting additional information about this bridge.

Scottish Bridges: 51. Kirkton of Glenisla Footbridge

On the third and final day of our Scottish bridge trip, we drove south from Braemar. We only planned to visit four bridges, but they included some of the best of the whole trip.

Our first stop was for a little footbridge spanning 18.9m over the River Isla at Kirkton of Glenisla. This was built in 1824 by John Justice Jr, whose work we had met the previous day at Crathie Suspension Bridge. The Justice family were blacksmiths, and everything about their bridge work was informed by that background.

It's hard to overstate the historical significance of this bridge. You won't find it mentioned in the normal books on bridge engineering history, but it is almost certainly the oldest unaltered reasonably pure cable-stayed bridge in Britain, and I think it might possibly be the oldest surviving example anywhere.

It was Listed Category B in 1971 (it's also an Ancient Monument), with the following brief description:

Footbridge. Wrot-iron suspension with wood decking and stone abutments. Arched approaches have plaques inscribed, "Jn. Justice, Dundee 1824". Picturesque.

That's both mildly inaccurate and utterly inadequate - I'll boldly suggest this is one of the most important historic bridges in the UK. Earlier bridges with stays had been built in Scotland from 1816-17 at Galashiels, Dryburgh and King's Meadows, but none survived for long. They were well-reported by Robert Stevenson in his 1821 article Description of Bridges of Suspension, so may well have been known to Justice.

In form, it is a twin-pylon single-span cable-stayed bridge. Three rod stays anchor each pylon leg to ground (varying in diameter from 11/16" to 7/8"), and four rod stays, each 9/16" in diameter, connect the main span to each pylon leg. Two of the span stays meet at midspan on each side of the bridge. There are several great diagrams at the RCAHMS website, but this one is perhaps clearest.

The stays provide the main structural support, but not the only one. Some of the rods in the bridge balustrades sag downwards, a little like suspension cables, and are anchored to the pylons in a manner which suggests they also help hold up the bridge. The sag is extremely shallow so it's hard to believe they contribute much.

The deck itself is astonishingly slender. There are two iron edge members below the timber decking, each a simple flat bar, and flat bar cross-members connect these at intervals matching the stay connections and parapet posts. The main edge members seem to serve the main function of providing the stays with a tension tie to react against. It's no great surprise to see that the deck has deformed over time and taken up a slightly twisted profile.

Much of the pleasure of seeing this bridge comes from realising quite how startlingly skeletal its structure is. However, as much pleasure comes from the myriad of small details, such as the way the stays are variously bolted through the pylons as well as connected to clamps passing around them. They give the clear impression that this was an entirely experimental bridge, with additional elements added one-by-one until the builder was satisfied it would not fall.

The parapets give the same impression, with a jumbled assortment of bars and flats thrown together around the main support elements.

The bridge forms part of the 64-mile Cateran Trail, a walking route which is named for cattle thieves who once roamed the area. The reason for construction of the bridge itself is now unknown.

Further information:

• Google maps / Bing maps
• RCAHMS
• British Listed Building
• Angus SMR
• Scottish Suspension Bridges (Hume, Scottish Archaeological Forum Vol. 7, 1977)
• The 19th century iron bridges of Northeast Scotland (Day, Journal of the Society for Industrial Archaeology, 1998)
• Some iron suspension bridges in Scotland 1816-1834 and their origins (Ruddock, The Structural Engineer, 2003)
• Civil Engineering Heritage - Scotland Highlands and Islands (Paxton and Shipway, 2007)