GRALISTAIR
Established Member
Not surprised by the bridge. The kinetic energy it absorbed would be huge.
Regarding the repairing of the route, has any consideration been given to accommodate the preparation works for overhead line electrification?
It would save having to close the line in the future.
There's a little bit more to electrification than sending some of the team out with some piles and a Movax. There will need to be a detailed design in place with specified piling locations before any groundwork can begin, and there will need to be a good ground survey (though I'm sure some of the data from the geotechnical people may find its way to the electrification planning team in the fullness of time). The specified piling locations have to take into account signalling, tunnels, culverts, bridges and will also have to take into account where tensioning and anchoring structures will be placed, as these require additional foundation structures.
But before any of that can be done, there needs to be a CGI of the route undertaken to assess where the signal sighting issues will arise and in these locations you desperately try and avoid tensioning or anchor structures and wire run overlaps, as they tend to require steelwork which gets in the way of your signals. Where it's not possible, signals may need to be moved to a gantry structure to aid sighting.
The boots on the ground bit is the end quarter of an electrification project, really.
There's a little bit more to electrification than sending some of the team out with some piles and a Movax. There will need to be a detailed design in place with specified piling locations before any groundwork can begin, and there will need to be a good ground survey (though I'm sure some of the data from the geotechnical people may find its way to the electrification planning team in the fullness of time). The specified piling locations have to take into account signalling, tunnels, culverts, bridges and will also have to take into account where tensioning and anchoring structures will be placed, as these require additional foundation structures.
But before any of that can be done, there needs to be a CGI of the route undertaken to assess where the signal sighting issues will arise and in these locations you desperately try and avoid tensioning or anchor structures and wire run overlaps, as they tend to require steelwork which gets in the way of your signals. Where it's not possible, signals may need to be moved to a gantry structure to aid sighting.
The boots on the ground bit is the end quarter of an electrification project, really.
Exactly.
On another thread is the link to the Leeds - Huddersfield project consultation documentation under the Transpennine Upgrade. In this you can see the outline designs for the OLE gantries. This is for a project that won’t be on site for 2-3 years.
Also, could it be explained what CGI means please?
Assuming my back-of-the-envelope calculation is right (2 x 72 tonne locos and 4 x 33 tonne carriages), that would be 139 Megajoules which, according to Wikipedia, is akin to having a decent-sized plane land on it.Kinetic Energy the bridge absorbed KE = 1/2 mv^2 a lot! Hence the delay
Assuming my back-of-the-envelope calculation is right (2 x 72 tonne locos and 4 x 33 tonne carriages), that would be 139 Megajoules which, according to Wikipedia, is akin to having a decent-sized plane land on it.
No, but those vehicles were still moving and contributing to the energy that had to be dissipated.The rear power car didn't hit it, nor at least one of the carriages.
Assuming my back-of-the-envelope calculation is right (2 x 72 tonne locos and 4 x 33 tonne carriages), that would be 139 Megajoules which, according to Wikipedia, is akin to having a decent-sized plane land on it.
The rear power car didn't hit it, nor at least one of the carriages.
IIRC, it was a couple hundred metres from the point of derailment to the bridge so there will have been almost no reduction in speed.I would have expected that the driver would have made a full brake application imediatly on derailing so that the speed would be reducing as it was crossing the viaduct so reducing the speed.
Rather surprised when I heard that the train involved in this sad incident was returning Northbound at almost full normal line speed.Kinetic Energy the bridge absorbed KE = 1/2 mv^2 a lot!
IIRC, it was a couple hundred metres from the point of derailment to the bridge so there will have been almost no reduction in speed.
Sorry, I meant specifically due to the application of the brakes.There will, as various wheels dragging in the ballast has quite a retardation effect.
In summary, the bridge and embankment repairs have been completed so they've now moved on to replacing the track (>500 m worth) and telecoms cables (400 m). Looking like November at this stage.Our engineers are now relaying over 500 metres of track following the recent completion of work to repair the bridge and embankment damaged in the accident.
Work will continue into November as our teams remove and replace the damaged track and relay 400 metres of telecoms cables.
Teams have worked day and night over the past few weeks to complete repairs to 70 metres of bridge parapets and remove the crane pad built over the Carron Water for the recovery of the carriages in September.
A considerable amount of engineering work is also being carried out to repair and extend drainage systems on the railway track and lineside embankments at the site...
That isn't much work so I'd expect completion in October.Network Rail have just published an update on repairs.
In summary, the bridge and embankment repairs have been completed so they've now moved on to replacing the track (>500 m worth) and telecoms cables (400 m). Looking like November at this stage.
Bit of a bummer for those of us getting the bus to work every day, but I appreciate you can't rush these things.
I expect that they would have drilled anchors into the existing brickwork.Looks like the new parapet sections are fairly large concrete blocks, can anyone explain how they’d be secured to the underlying existing bridge structure, or will they just be laid on a fairly normal mortar bed?
Hey Ho, why not let it wait until 2021.In summary, the bridge and embankment repairs have been completed so they've now moved on to replacing the track (>500 m worth) and telecoms cables (400 m). Looking like November at this stage.
Bit of a bummer for those of us getting the bus to work every day, but I appreciate you can't rush these things.
Looks like the a new in-situ poured concrete slab on top of the bridge so pretty easy to anchor something too. (The track height has increased over the years so plenty of depth available.)Looks like the new parapet sections are fairly large concrete blocks, can anyone explain how they’d be secured to the underlying existing bridge structure, or will they just be laid on a fairly normal mortar bed?
Presumably the scour protection walls under the bridge is the work that was already taking place?
Most of the delay was due to the investigation. The site was handed back to NR about 20 days ago, they will have had to do drainage work, regraded the embankment and completed the bridge work in that time.Just to make the point, the big accident (far more so than this one) at Norton Fitzwarren, near Taunton, in 1940, which from photographs had just as much if not more destroyed track and signalling etc than here at Stonehaven, was all back and running, with civils repaired, signals reinstated (and this was a junction, not plain line) in ... 48 hours from it happening.
Yes of course, so there could well be hidden rebar joining the poured slab to the parapet blocks as well, which means it’s basically all joined together forming a whole heavy mass.Looks like the a new in-situ poured concrete slab on top of the bridge so pretty easy to anchor something too. (The track height has increased over the years so plenty of depth available.)
Just to make the point, the big accident (far more so than this one) at Norton Fitzwarren, near Taunton, in 1940, which from photographs had just as much if not more destroyed track and signalling etc than here at Stonehaven, was all back and running, with civils repaired, signals reinstated (and this was a junction, not plain line) in ... 48 hours from it happening. Under wartime blackout conditions, with all the younger and fitter staff away in the military.
I was wondering that. The landslip at Polmont that happened the same day as Stonehaven arguably caused more extensive damage to the railway (~1 km of new track needed, with associated cabling and electrification gantries, and ~300 m worth of embankment to shore up, plus fixing the burst canal in the first place) and those repairs took about 6 weeks. With the bridge and embankment at Carmont now sorted (after ~20 days since the handover from RAIB), bar any lingering access issues for materials etc, the rest should be relatively straightforward right?That isn't much work so I'd expect completion in October.
True, but even long after the war, accident sites were recovered a lot quicker than they are now.In wartime there are differing rules. No investigations just get the damned assets back in use ASAP
But, by the same token, those detailed and painstaking investigations are the biggest reason why accidents are much less frequent now than they used to be.The modern obsession with investigation is killing the job. By all means investigate, but how many weeks does it take to investigate why a cutting slope slipped in extreme wet weather?
Indeed. Obviously 3 lost lives was tragic but the being the first deaths for 13 years shows a fantastic safety record.But, by the same token, those detailed and painstaking investigations are the biggest reason why accidents are much less frequent now than they used to be.
I wholeheartedly agree. I travel that route every day (in fact, I would have been on the train following the 0638 had it not been cancelled at ABD) and a few extra weeks getting the bus to work is worth it if reduces the chance of this happening again.But, by the same token, those detailed and painstaking investigations are the biggest reason why accidents are much less frequent now than they used to be.