HST derailment, near Stonehaven, 12th August 2020

[whole diary]

[grahame]

From Rail Advent

Tomorrow, Tuesday, November the 3rd, will see the railway line reopen between Aberdeen and Dundee after repair works following the tragic derailment near Stonehaven back in August.

[bradshaw]

Two trains run over the section today as shown on RTT^» (Real Time Trains - website)
https://www.realtimetrains.co.uk/search/detailed/CAARMNT/2020-11-02/0200-0159?stp=WVS&show=all&order=wtt

[grahame]

from the RAIB^▸ (Rail Accident Investigation Branch) via email notifications linking to ((here))

Between about 06:35 hrs and 07:40 hrs on 4 December 2020, two passenger trains passed through an emergency speed restriction located between Laurencekirk and Portlethen stations, at speeds of up to 100 mph (160 km/h), significantly exceeding the temporary maximum permitted speed of 40 mph (64 km/h). The first train was travelling north from Dundee to Inverness, the second was travelling south from Inverness to Edinburgh. The emergency restriction had been introduced as a precaution in case forecast heavy rainfall caused ground movements affecting the safety of the railway.

Neither of the train drivers was aware of the emergency speed restriction at the time they drove their trains over the affected section of track. The events were identified after a Network Rail signaller noticed the relatively short time taken for the second train to pass through the area. The first overspeed was then identified using electronic records of train movements. There were no injuries or damage as a result of these incidents.

Our investigation will determine the sequence of events that led to the incidents and include consideration of:
* the processes for advising train drivers of emergency speed restrictions
* any overlap with issues identified during the on-going RAIB investigation of the fatal accident on 12 August 2020 at Carmont, a location within the area covered by this emergency speed restriction (although there was no emergency speed restriction at Carmont on the 12 August)
* any relevant underlying factors.

[grahame]

Just after I posted than, found this in the Press and Journal

'Outrageous negligence': Sister of tragic driver hits out as trains reach double the speed limit amid landslip fears on north-east line

Rail bosses have come under fire after train drivers were clocked at 100mph on tracks where a 40mph emergency limit had been put in place amid landslip fears.

The drivers, who were on the Aberdeenshire stretch of line where there was a fatal crash just four months before, had not been told about the need to slow down due to the conditions by higher-ups.

Last night, the family of Brett McCullough, the driver killed in August's derailment, branded the dangerous incident in December "outrageous negligence" so soon after the tragedy which cost his life.

[FarWestJohn]

I thought the line speed through there was 75 mph before the restriction?

[stuving]

I thought the line speed through there was 75 mph before the restriction?

Where "there"? At the accident site the limit was 65/HST75, but if (as implied by the RAIB^▸ (Rail Accident Investigation Branch) text) the restriction applied over a longer section of track, higher limits would apply there. Through Laurencekirk it's 90/HST100, and through Portlethen it's 80/HST100, and elsewhere in between it's between 75 and 100. (Actually those are from 2016, but unlikely to have been changed.)

[grahame]

From National Rail

Disruption between Aberdeen and Dundee expected until the end of service on Sunday 17 January

Urgent repairs to a bridge between Laurencekirk and Stonehaven due to damage caused by severe weather has resulted in all lines being closed.

Disruption is expected to continue until at least the end of service on Sunday 17 January.

and from the Evening Express (Aberdeen) reported at 17:30 on 15.1.2021

Shock as part of north-east rail bridge collapses close to site of Stonehaven train tragedy

A trade union says the situation on Scotland?s railways is ?becoming terrifying? after part of a bridge collapsed approximately one mile from the site of the Stonehaven train derailment.

Train services from Aberdeen were disrupted earlier today after the side wall of a bridge near Stonehaven gave way ? close to the scene of the crash at Carmont last August, which left three men dead.

Unlike August?s tragedy, the most recent incident was not caused by a landslip.

Network Rail said the bridge was damaged ?due to weather conditions?.

[continues]

[stuving]

Now reported on the BBC^» (British Broadcasting Corporation - home page), with a picture:

Part of rail bridge collapses near fatal Stonehaven derailment site

A 24m section of the bridge parapet collapsed one mile from where a fatal crash took place

Part of a rail bridge has collapsed near the site of the fatal Stonehaven train derailment.

A 24m (79ft) section of the side wall has fallen from the bridge, about a mile north of where three people died when a train left the track and crashed last August.

Network Rail said it was a "structural fault" and not caused by a landslip.

The line between Aberdeen and Dundee remains closed while structural engineers assess the fault.

The structure is located three miles north of Carmont signal box. The collapse was discovered just before 10:00 on Friday.

The rail company said the damage to the parapet was "extensive" and that the line was expected to be closed for a "significant" period of time while repairs to the bridge take place.
The BBC is not responsible for the content of external sites.View original tweet on Twitter
1px transparent line

The Network Rail Twitter account told followers engineers would be working around the clock to complete repairs.

Specialist staff are also checking similar bridges as a precaution.

The line between Aberdeen and Dundee had just reopened in November, nearly three months after the Stonehaven derailment.

It's really nearer two miles north-east, at East Croft of Carmont. Now, work was going on in the river Carron to protect that bridge's abutments from scour, from before the accident and finishing in September. There's a picture here on railscot showing it from below.

The collapse appears to be more off the bridge itself than on, where there does seem to be a lot of soil fill under the track. So presumably that got wet and pushed the parapet wall - and the sidewall of the bridge lower down - off. Of course Story's works may also have given it a bit of a shoogle to help it along.

[IndustryInsider]

Great view of the stratification of a railway line there.  I wouldn't have been wanting to be walking along the river below when the parapet fell!

[stuving]

On second thoughts (or rather looks), I think it is "just" the parapet that's gone. Now, what's going to be the current Network Rail way of repairing that? Rebuilt it out of masonry as original? An engineered system, such as a steel wall pinned to the other side (with long pins, obviously)? It's not clear "the usual suspect" - reinforced concrete - is going to be any easier here.

[TonyN]

On second thoughts (or rather looks), I think it is "just" the parapet that's gone. Now, what's going to be the current Network Rail way of repairing that? Rebuilt it out of masonry as original? An engineered system, such as a steel wall pinned to the other side (with long pins, obviously)? It's not clear "the usual suspect" - reinforced concrete - is going to be any easier here.

Looking at the attached photo of the derailment site after repair they have replaced the stone with reinforced concrete.

[stuving]

On second thoughts (or rather looks), I think it is "just" the parapet that's gone. Now, what's going to be the current Network Rail way of repairing that? Rebuilt it out of masonry as original? An engineered system, such as a steel wall pinned to the other side (with long pins, obviously)? It's not clear "the usual suspect" - reinforced concrete - is going to be any easier here.

Looking at the attached photo of the derailment site after repair they have replaced the stone with reinforced concrete.

Concrete blocks yes, but reinforced? You can string blocks together for strength, but those look like big separate blocks used as quick-build masonry. But if they've been practicing on the bridge next door, and already have them, no doubt that's exactly what they will do.

...actually I think there's a subtle difference between the two bridges, similar though they look. At West Carmont, the parapet taken off by the train was about half above the track level. This time, it's almost all below track level, retaining a deeper bed of fill. So I would not be surprised if NR^» (Network Rail - home page) feel they need to pin (or nail) the wall (not a true parapet) into the formation.

[Bmblbzzz]

They appear to have reinforced the river bank as well (unless that had been done previously, but it looks new).

[stuving]

They appear to have reinforced the river bank as well (unless that had been done previously, but it looks new).

I think that was part of the same work at both bridges, starting well before the accident, to protect them from scour.

[paul7575]

On second thoughts (or rather looks), I think it is "just" the parapet that's gone. Now, what's going to be the current Network Rail way of repairing that? Rebuilt it out of masonry as original? An engineered system, such as a steel wall pinned to the other side (with long pins, obviously)? It's not clear "the usual suspect" - reinforced concrete - is going to be any easier here.

Looking at the attached photo of the derailment site after repair they have replaced the stone with reinforced concrete.

Concrete blocks yes, but reinforced? You can string blocks together for strength, but those look like big separate blocks used as quick-build masonry. But if they've been practicing on the bridge next door, and already have them, no doubt that's exactly what they will do.

...actually I think there's a subtle difference between the two bridges, similar though they look. At West Carmont, the parapet taken off by the train was about half above the track level. This time, it's almost all below track level, retaining a deeper bed of fill. So I would not be surprised if NR^» (Network Rail - home page) feel they need to pin (or nail) the wall (not a true parapet) into the formation.

I wonder if they?ve increased the track cant to improve overall line speed?  Does the other side of this bridge still have a bit more parapet above the ballast? 

Would be pretty scary if they?ve just generally increased the ballast depth and it?s introduced a failure mode...

Paul