Reading Station improvements

[whole diary]

[stuving]

Presumably these are the two old relief line spans. They carried one track each, so I think they would need to be used side by side. At roughly 4 m wide by 16 long, they ought to be long enough to span a four-track line.

The other spans that were removed had carried the goods lines, and had been unused for several years. While I have never seen anything to confirm this, I think they had been condemned as unsafe - you could see daylight through the holes in them as you walked underneath.

Oh, and the new bridge is most definitely made of steel. Perhaps deck describes it better (orthotropic deck, if you want to be technical).

[ellendune]

Oh, and the new bridge is most definitely made of steel. Perhaps deck describes it better (orthotropic deck, if you want to be technical).

Orthotropic means, if I recall correctly, that it spans in two dimensions both cross and along the bridge deck. 

[stuving]

Orthotropic means, if I recall correctly, that it spans in two dimensions both cross and along the bridge deck. 

The usage of the term is a bit more specific - the deck surface is a plate that forms an essential part of the structure. The lengthwise and crosswise members are then welded to the bottom of this plate. For example, these might be U-sections that form box girders only when joined to the deck plate. This saves a lot of weight compared to a girder bridge with a deck plate loosely fixed on top of it.

At Reading, I am sure that one of the objectives was to provide an unobstructed deck so that a variety of sweeping curves and trackwork can be installed, rather than being restricted to parallel plain tracks. Obviously a design with no members above the deck, between sides that are very far apart, is ideal.

[ellendune]

Orthotropic means, if I recall correctly, that it spans in two dimensions both cross and along the bridge deck. 

The usage of the term is a bit more specific - the deck surface is a plate that forms an essential part of the structure. The lengthwise and crosswise members are then welded to the bottom of this plate. For example, these might be U-sections that form box girders only when joined to the deck plate. This saves a lot of weight compared to a girder bridge with a deck plate loosely fixed on top of it.

At Reading, I am sure that one of the objectives was to provide an unobstructed deck so that a variety of sweeping curves and trackwork can be installed, rather than being restricted to parallel plain tracks. Obviously a design with no members above the deck, between sides that are very far apart, is ideal.

It also allow the deck to be shallower maximising the height under the bridge

[stuving]

It also allow the deck to be shallower maximising the height under the bridge

Quite so, in the sense that otherwise the girders or stiffeners omitted from above the deck would have to be replaced by something deeper than the current structure underneath it.

On the other hand, the new deck is not any shallower than the deck of the old spans still there. In fact, its underside sits level with theirs (you can see this on Street View). I don't have any evidence that shows its height relative to the removed spans.

This is rated as a low bridge, with signs saying 15'6" (4724 mm). The road is even widened just south of the bridge so that artics can do a U-turn if they need to - and I have seen it happen.
 

[ellendune]

So I suppose the issue was to not make it any deeper while giving the flexibility that you mentioned.

[Electric train]

Anyone know if this is a bridge that is already removed or one that is still there?

I did not think there was a bridge with a long enough span at Reading.

Great Central Railway to 'bridge' the gap between Leicester and Nottingham within five years (Using Bridge from Reading)
GREAT Central Railway is hoping to ^bridge^ the gap between the Loughborough heritage line and the Nottingham section to the north with the news a connection is to be built over the Midland Mainline.
GCR^» (Gloucester - next trains) has launched a ^1m Bridge To The Future fund-raising appeal after forming a parnership with Network Rail to build a bridge over the Midland Main Line at Loughborough.
Design work is underway and the new structure made up of two reclaimed rail bridges from Reading is expected to be in place running over the four tracks of the Midland Mainline by mid-2015 - allowing the demolished 500m link between the two sections, rejoining Leicester to Nottingham via an 18 mile heritage railway.
 .......

After all the discussion on the science of bridges here's a link to GCR http://www.gcrailway.co.uk/2013/05/bridge-to-the-future-fundraising-appeal/

[stuving]

Obviously I did not read the GCR^» (Gloucester - next trains) item carefully - my mistake.

It does say that the bridge will take the rebuilt GCR main line over the NR^» (Network Rail - home page) line. As this is close to Loughborough station, the tracks are spread out over well over 16 m, and the bridge will only carry a single track.

The picture does not look like the relief line spans, more like the older goods line spans but substantially rebuilt.

[Electric train]

Anyone know if this is a bridge that is already removed or one that is still there?

I did not think there was a bridge with a long enough span at Reading.

Great Central Railway to 'bridge' the gap between Leicester and Nottingham within five years (Using Bridge from Reading)
GREAT Central Railway is hoping to ^bridge^ the gap between the Loughborough heritage line and the Nottingham section to the north with the news a connection is to be built over the Midland Mainline.
GCR^» (Gloucester - next trains) has launched a ^1m Bridge To The Future fund-raising appeal after forming a parnership with Network Rail to build a bridge over the Midland Main Line at Loughborough.
Design work is underway and the new structure made up of two reclaimed rail bridges from Reading is expected to be in place running over the four tracks of the Midland Mainline by mid-2015 - allowing the demolished 500m link between the two sections, rejoining Leicester to Nottingham via an 18 mile heritage railway.
 .......

After all the discussion on the science of bridges here's a link to GCR http://www.gcrailway.co.uk/2013/05/bridge-to-the-future-fundraising-appeal/

[didcotdean]

Short BBC^» (British Broadcasting Corporation - home page) report from 2011 on the bridge just after it was removed plus one with more detail, although it seems they have changed what they are going to do with the donated bridges.

[stuving]

Curiouser and curiouser...

My initial thought was that this reporter has got mixed between the two bridges taking the GCR^» (Gloucester - next trains) over  the A60 and the Midland mainline. However, this report:
http://www.railwaymagazine.co.uk/news/network-rail-gives-massive-boost-to-great-central-bridge-project
(which is awfully similar to the British Heritage Railways one) ends with this:

Spanning the Midland Main Line is still the major aspect of the project, and this will be accomplished as a single span.

So it looks as if there are to be two new bridges - the question is whether both use old Reading spans. If they do, you would have thought that was worth mentioning, not least by GCR and GCR(N)!

The description of the two spans to be used side by side over the A60 as dating from the 1970s must mean they are the relief line ones.

[Red Squirrel]

Curiouser and curiouser...

My initial thought was that this reporter has got mixed between the two bridges taking the GCR^» (Gloucester - next trains) over  the A60 and the Midland mainline. However, this report:
http://www.railwaymagazine.co.uk/news/network-rail-gives-massive-boost-to-great-central-bridge-project
(which is awfully similar to the British Heritage Railways one) ends with this:

Spanning the Midland Main Line is still the major aspect of the project, and this will be accomplished as a single span.

So it looks as if there are to be two new bridges - the question is whether both use old Reading spans. If they do, you would have thought that was worth mentioning, not least by GCR and GCR(N)!

The description of the two spans to be used side by side over the A60 as dating from the 1970s must mean they are the relief line ones.

The GCR are clear on this:

The link will be single track to contain costs and will reuse the two bridge decks formerly over Caversham Road in Reading

(source: http://www.gcrailway.co.uk/unify/unify-more-information/

There's another issue - the embankment needs to be narrower than the original due to a requirement for an access road, and to allow deviation around the Preci-Spark factory.

The GCR's website http://www.gcrailway.co.uk/unify/ illustrates the MML^» (Midland Main Line. - about) bridge as two spans with a central pier.

[stuving]

Exactly - and two years ago there were clear plans for rebuilding the A60 bridge.

Looking carefully through the three different GCR^» (Gloucester - next trains) articles on this, I can find words that say:"We have to raise one million pounds, to put two previously recovered bridge decks in place by the end of 2015." and " On the northern section of the GCR, the bridge across the A60 also needs upgrading."

So why not explain - for the benefit of anyone who saw the earlier news - that the reused spans were going to be used on the A60 bridge, but that is now going to be upgraded a different way? If it's because the A60 bridge is on the GCR(N)'s side of the gap, it does make you wonder how well the two groups will co-operate, or even merge, after the link-up.

[Electric train]

Exactly - and two years ago there were clear plans for rebuilding the A60 bridge.

Looking carefully through the three different GCR^» (Gloucester - next trains) articles on this, I can find words that say:"We have to raise one million pounds, to put two previously recovered bridge decks in place by the end of 2015." and " On the northern section of the GCR, the bridge across the A60 also needs upgrading."

So why not explain - for the benefit of anyone who saw the earlier news - that the reused spans were going to be used on the A60 bridge, but that is now going to be upgraded a different way? If it's because the A60 bridge is on the GCR(N)'s side of the gap, it does make you wonder how well the two groups will co-operate, or even merge, after the link-up.

I think the reason why the bridge over the MML^» (Midland Main Line. - about) is happening and the A60 is not is due to NR^» (Network Rail - home page) having a project team in place this makes it easier for GCR to bridge that part of the gap to do the A60 I suspect means engaging with a County Council highways and the Highways Agency who are unlikely to have a project team in place

[Jason]

It looks as though preparations are happening for the laying of track into P11 on the London side of the station.
The ballast has been leveled and the route marked out in blue.