Bridging the Gap: How the Severn Bridge Was Built - BBC Timeshift

[whole diary]

[JayMac]

A fascinating and heartfelt look at the design and construction of the Severn Bridge, which turned 50 last month. Why the bridge had to be built is covered too.

The programme is centred around first hand accounts from those who were involved in the design and construction. From design engineers to steel erectors via rescue launch crew, tea boys and toilet cleaners.

We perhaps forget that the Severn Bridge was a huge leap forward in bridge design. Britain led the world in this field. Every subsequent long span suspension bridge built anywhere in the world has aped this British design.

http://www.bbc.co.uk/iplayer/episode/b0803m60/timeshift-series-16-1-bridging-the-gap-how-the-severn-bridge-was-built

The programme is available on BBC^» (British Broadcasting Corporation - home page) iPlayer until Tuesday 15th November 2016.

[stuving]

We perhaps forget that the Severn Bridge was a huge leap forward in bridge design. Britain led the world in this field. Every subsequent long span suspension bridge built anywhere in the world has aped this British design.

I thought the context of the design was rather muddled. Only a brief mention of the Forth Bridge, which was (and still is) longer. That was being designed when the Tacoma Narrows bridge collapsed, leading to a lot of wind-tunnel testing (to make sure the air flowed through the girders nicely) and several design additions. Almost no mention either of the Humber Bridge, which finally beat the Americans for length.

The point of these three is that all were designed by Freeman Fox and Partners, who themselves weren't named until right at the end. And those interviewed worked for Freemans and for various contractors, who weren't named, and how these companies collaborated was never explained.

But it was a very interesting programme.

Incidentally, Freeman Fox and Partners became part of Hyder Consulting, design engineers for - guess what - Manchester Victoria and its new roof! And they are now part of Arcadis NV.

[Tim]

We perhaps forget that the Severn Bridge was a huge leap forward in bridge design. Britain led the world in this field. Every subsequent long span suspension bridge built anywhere in the world has aped this British design.

I thought the context of the design was rather muddled. Only a brief mention of the Forth Bridge, which was (and still is) longer. That was being designed when the Tacoma Narrows bridge collapsed, leading to a lot of wind-tunnel testing (to make sure the air flowed through the girders nicely) and several design additions. Almost no mention either of the Humber Bridge, which finally beat the Americans for length.

The point of these three is that all were designed by Freeman Fox and Partners, who themselves weren't named until right at the end. And those interviewed worked for Freemans and for various contractors, who weren't named, and how these companies collaborated was never explained.

But it was a very interesting programme.

Incidentally, Freeman Fox and Partners became part of Hyder Consulting, design engineers for - guess what - Manchester Victoria and its new roof! And they are now part of Arcadis NV.

I tend to agree.  A good programme but rather muddled.  Didn't mention the Forth Road Bridge which is a much more conventional deck design built by Freeman Fox and Partners just a few years before. 

Nor did it mention that in 1977, just 11 years after opening, the Severn bridge was reduced to a single lane each way until expensive strengthening and a huge amount of extra steel was added to the towers.  Further strengthening was needed in to the towers and deck in the 1980s. 

[chrisr_75]

We perhaps forget that the Severn Bridge was a huge leap forward in bridge design. Britain led the world in this field. Every subsequent long span suspension bridge built anywhere in the world has aped this British design.

I thought the context of the design was rather muddled. Only a brief mention of the Forth Bridge, which was (and still is) longer. That was being designed when the Tacoma Narrows bridge collapsed, leading to a lot of wind-tunnel testing (to make sure the air flowed through the girders nicely) and several design additions. Almost no mention either of the Humber Bridge, which finally beat the Americans for length.

The point of these three is that all were designed by Freeman Fox and Partners, who themselves weren't named until right at the end. And those interviewed worked for Freemans and for various contractors, who weren't named, and how these companies collaborated was never explained.

But it was a very interesting programme.

Incidentally, Freeman Fox and Partners became part of Hyder Consulting, design engineers for - guess what - Manchester Victoria and its new roof! And they are now part of Arcadis NV.

I tend to agree.  A good programme but rather muddled.  Didn't mention the Forth Road Bridge which is a much more conventional deck design built by Freeman Fox and Partners just a few years before. 

Nor did it mention that in 1977, just 11 years after opening, the Severn bridge was reduced to a single lane each way until expensive strengthening and a huge amount of extra steel was added to the towers.  Further strengthening was needed in to the towers and deck in the 1980s. 

It's also suffering from similar issues with main suspension cable corrosion as per the (first) Forth Road Crossing - a programme of works has recently been completed. It also included installing what are perhaps best described as fairy lights along the main suspension cables, so the old girl now looks all pretty at night!

[Tim]

I noticed the pretty lights from my Rail Replacement coach last week. 

[anthony215]

The old Severn bridge still spends a good deal of time shut when there is high winds due to lack of windbreakers on the sides compared to the newer bridge which isn't closed anywhere near as often.

Still I find the old bridge to be nice to drive across (Except when its  windy  and I have a heavily loaded National Express coach)

[chrisr_75]

The old Severn bridge still spends a good deal of time shut when there is high winds due to lack of windbreakers on the sides compared to the newer bridge which isn't closed anywhere near as often.

Still I find the old bridge to be nice to drive across (Except when its  windy  and I have a heavily loaded National Express coach)

The bridge deck appears to be much more low slung on the new bridge which I think helps with wind deflection and general sense of exposure, whereas the road surface is a sort of raised platform on the old bridge, so feels very exposed in some conditions.

I do like the old bridge and tend to use it in preference over the second Severn crossing as the M48 sees a lot less traffic, so a little more progress can be made resulting in no time loss, although it can indeed be rather 'lively' in anything more than a gentle breeze! It also doesn't have the 50mph limit prior to the tolls (I believe the result of a few nasty accidents at the toll booths), so you don't end up with some @rse in a coach tailgating you on the 50ish mph run up to the toll booths 

[anthony215]

The old Severn bridge still spends a good deal of time shut when there is high winds due to lack of windbreakers on the sides compared to the newer bridge which isn't closed anywhere near as often.

Still I find the old bridge to be nice to drive across (Except when its  windy  and I have a heavily loaded National Express coach)

The bridge deck appears to be much more low slung on the new bridge which I think helps with wind deflection and general sense of exposure, whereas the road surface is a sort of raised platform on the old bridge, so feels very exposed in some conditions.

I do like the old bridge and tend to use it in preference over the second Severn crossing as the M48 sees a lot less traffic, so a little more progress can be made resulting in no time loss, although it can indeed be rather 'lively' in anything more than a gentle breeze! It also doesn't have the 50mph limit prior to the tolls (I believe the result of a few nasty accidents at the toll booths), so you don't end up with some @rse in a coach tailgating you on the 50ish mph run up to the toll booths 

Have u seen some of the lorries one the approaches to the tolls?    Anyway the road surface on the new bridge  isn't as good as it used to be and I admit the old bridge does seem smoother to drive over these days which I do regulary if its open and there is congestion on the new bridge

[chrisr_75]

The old Severn bridge still spends a good deal of time shut when there is high winds due to lack of windbreakers on the sides compared to the newer bridge which isn't closed anywhere near as often.

Still I find the old bridge to be nice to drive across (Except when its  windy  and I have a heavily loaded National Express coach)

The bridge deck appears to be much more low slung on the new bridge which I think helps with wind deflection and general sense of exposure, whereas the road surface is a sort of raised platform on the old bridge, so feels very exposed in some conditions.

I do like the old bridge and tend to use it in preference over the second Severn crossing as the M48 sees a lot less traffic, so a little more progress can be made resulting in no time loss, although it can indeed be rather 'lively' in anything more than a gentle breeze! It also doesn't have the 50mph limit prior to the tolls (I believe the result of a few nasty accidents at the toll booths), so you don't end up with some @rse in a coach tailgating you on the 50ish mph run up to the toll booths 

Have u seen some of the lorries one the approaches to the tolls?    Anyway the road surface on the new bridge  isn't as good as it used to be and I admit the old bridge does seem smoother to drive over these days which I do regulary if its open and there is congestion on the new bridge

Yes, plenty of the cars are bad there too, little do they realise there is often a camera van very well hidden on the overbridge just inside the 50 limit...! It's a speed limit I wholeheartedly agree with and observe as it is keeping the toll operators a little bit safer in their workplace. To balance my previous jocular comments, the worst of the coaches tend to be the smaller operators, NEx & Megabus branded vehicles are generally ok except for a slight tendency to indicate and go regardless of whether their target lane is suitably clear or not 

[patch38]

If you don't want to watch it on the iPlayer, it's repeated on BBC^» (British Broadcasting Corporation - home page) Four at 20:00 tonight.