Bridges news roundup

I'm preparing posts on a handful of bridges I recently visited in London and Birmingham. Until those are ready, have some news:

Plan for viewing platform at top of Forth Rail Bridge
Yes please!

A bridge from the future that never was
I reported positively on Calatrava's Katehaki Bridge, in Athens, back in May. Here's a gloomier appraisal: "The bridge has never really been loved."

The architect behind 'eyesore' Dresden bridge
Unesco's Most Wanted speaks out.

Canberra bridge wins prestigious design award
Landscape architecture award for masterplan including unpretentious little bridge.

Point Resolution Bridge / Warren & Mahoney
Slickly futuristic. Super-slender piers. Structurally irrelevant arch features, sorry "armatures". Good? Bad? Who knows. Many more photos here.

Høse Bridge / Rintala Eggertsson Architects
A very "industrial" looking bridge in a natural landscape. I'm unconvinced by the desire to enclose the bridge in a setting like this, but it's unfair to judge only by photos.

Craigieburn Bypass / Tonkin Zulaikha Greer + Taylor Cullity Lethlean
A very different setting, another enclosed bridge.

Amazing camouflaged bridge
Go on, you must be able to think of a few more bridges out there that could do with being turned "invisible".

Cumbria Bridges: 11. Bridge House, Ambleside

This bridge is a curiosity more than anything else.

In Bridges in Britain, G Bernard Wood described the bridge as follows: "The tiny bridge-house is a waif of Time, stranded between road and car-park".

It was reportedly built over 300 years ago as an apple store for the nearby Ambleside Hall. It was apparently constructed over Stock Ghyll in order to avoid land taxes.

In 1926, it was purchased and passed to the care of National Trust, who still use it as an information centre and shop.

Further information:

• Google maps / Bing maps
• British Listed Buildings
• Bridges in Britain (Wood, 1970)
• An Encyclopaedia of Britain's Bridges (McFetrich, 2010)
  
  
  
   
  
  

Reminder: Footbridge 2014 call for papers

Here's a reminder as the deadline is now approaching:

The ever-popular Footbridge conference has announced a call for papers for its 2014 event. The deadline to submit abstracts is 30th September 2013.

The conference theme is "Footbridges: Past, Present and Future", and papers have been invited addressing the following sub-themes:

1. Historical and heritage structures
2. Dynamic response and structural behaviour
3. Inspirations in footbridge design
4. Planning, design and construction of sustainable footbridges
5. Advances in materials technology for footbridge construction
6. Future directions in footbridge design and construction

Cumbria Bridges: 10. Trevor Woodburn Bridge

Now, here's a quite remarkable little bridge, which I think is totally unknown beyond its immediate vicinity but which easily deserves to be better publicised.

It lies on a foot and cycle trail connecting Elterwater to Skelwith Bridge, near Ambleside in Cumbria. It spans the River Brathay a short distance upriver from the waterfall, Skelwith Force. The creation of the trail was proposed in 1998 by local man Trevor Woodburn, and the bridge is named after him. It was completed at the end of 2006, and officially opened in July 2007.

The bridge was designed and fabricated by specialist architectural and sculptural metalwork firm Chris Brammall Ltd, who have also been responsible for some highly sculpted bridge parapets at Staveley and Sunderland. It cost £225,000, spanning 20m and weighing 16 tonnes.

The bridge deck consists of metal plate on steel members, while the parapets comprise a series of steel flat posts supporting an oak handrail. According to the designer's website, the geometry of the posts was "inspired by the tectonic pressure patterns in the surrounding rock faces".

The posts each have a slightly different geometry, with a slight indentation in profile developing towards midspan into a pronounced kink. The effect is to create an intriguing sculptural surface which presents an attractive profile from almost any perspective, yet dissolves entirely on a closer view.

The inner and outer surfaces of the parapet are formed from the same geometry yet visually are very different.

I think it's a gorgeous little bridge, and a genuine enhancement to visually and environmentally surroundings.

Further information:

• Google maps / Bing maps

Cumbria Bridges: 9. CKPR Bridge 75, Crozier Holme

Finally, here's the last of this set of disused railway bridges on the Cumbria, Keswick and Penrith railway lines.

Bridge 75 is an upright bowstring truss spanning 101 feet. For this bridge, I have a copy of a bridge record drawing, taken from John Rapley's book (see link at the end of the post). This shows the bridge before any strengthening was added in 1931-3. You can compare this against the photographs to see what was changed.

Of the various upright trusses on the line, this one has the most substantial overhead bracing. Otherwise, it is broadly similar to the others. It can be seen looking down to the river from the adjacent A66 highway bridge.

For anyone who would like to visit these bridges, there are details and directions in the Bowstrings over the Greta leaflet (linked below) and also on the Lake District Miles Without Stiles website. Free parking is available next to Keswick leisure centre, and there's a splendid pub in Threlkeld where weary, hungry or thirsty pontists can rest before returning along the route.

Further information:

• Google maps / Bing maps
• Bowstrings over the Greta (ICE)
• ICE PHEW database
• Forgotten Relics of an Enterprising Age
• Keswick to Penrith Railway Re-opening
• Thomas Bouch: The Builder of the Tay Bridge (Rapley, 2007)

Cumbria Bridges: 8. CKPR Bridge 74

I'm nearing the end of this set of bridges which formerly comprised part of Thomas Bouch's Cockermouth Keswick and Penrith Railway (CKPR) line.

This penultimate bridge is another upright bowstring truss. Unlike the previous examples, Bridges 69 and 71, this one has overhead bracing between the trusses, although so little as to be barely worth having.

The bridge lies a short distance to the east of a lovely, short little railway tunnel. It spans 122 feet and has a pronounced skew. As with most of the other bridges on the line, it was strengthened during its lifetime by the addition of new cross-girders, additional diagonal bracing struts to the top chord of the trusses, and additional vertical stiffening on the face of the arches. You can see clearly in the photographs how much heavier the strengthening members are compared to the original metalwork.

Although the railway line was closed in 1972, and converted to a foot/cycle trail quite recently, there are proposals to reopen the entire line as a railway (not just the Keswick to Threlkeld section forming the trail). These plans are being promoted by an independent group, not by any government body, and I have to say I think the likelihood of it ever happening is somewhere very close to nil.

They argue that the retention of the original railway bridges would make it easier to reinstate a railway line, but from what I saw when I visited, the present cycle and foot trail is extremely popular, and diverting it would be an expensive and possibly unpopular option.

Although the bridges may broadly have the strength to carry local passenger services, they are not in marvellous condition and would require close examination, repair and repainting to be of any use for a new railway line. There are difficult obstacles elsewhere on the route, where the original track formation has not been protected against encroachment, and it seems unlikely to me that there is a business case of sufficient strength to attract the necessary private investment.

Further information:

• Google maps / Bing maps
• Bowstrings over the Greta (ICE)
• ICE PHEW database
• Forgotten Relics of an Enterprising Age
• Keswick to Penrith Railway Re-opening
• Thomas Bouch: The Builder of the Tay Bridge (Rapley, 2007)

Cumbria Bridges: 7. CKPR Bridge 73, Rowsome

This is the last of the "upside-down" bridges as you head east along the Keswick to Threlkeld trail. This one is the shortest span at 80 feet.

Unlike the other two similar structures I've already covered, this bridge has retained small X-frame parapets, giving it quite a different appearance. It's still difficult to imagine the bridge as it must have been when it carried rail traffic however. I assume it had a timber deck with the rails supported on large longitudinal timbers, width the crossbeam outriggers supporting a maintenance footpath.

I was able to get a better view from directly underneath this bridge, showing the plate girder which was added when the bridge was strengthened in 1924-8. I wonder how the load was shared between the new girder and the original bowstring trusses, and suspect the girder did the lion's share of the work after it was introduced.

It's interesting to compare the two side views of the bridge in these photographs. The north face is considerably "greener" than the south, as you might expect. I wonder what the original engineers, Thomas Bouch and colleagues, would think of their structures being left in such a visibly dilapidated state. Perhaps they would just be pleased to see the bridge still in use, nearly 150 years after the railway line was originally built.

Further information

• Google maps / Bing maps
• Bowstrings over the Greta (ICE)
• ICE PHEW database
• Forgotten Relics of an Enterprising Age
• Keswick to Penrith Railway Re-opening
• Thomas Bouch: The Builder of the Tay Bridge (Rapley, 2007)