Severn Beach Line - services and incidents (merged posts)

[whole diary]

[Red Squirrel]

GWR^▸ (Great Western Railway) clearly think the River Avon had a promotion...

Meanwhile:

Flood alert for Tidal River Avon at Bristol, Pill and Shirehampton

Tides are expected to be higher than usual due to spring tides. First forecast high water is 20:30 on 21/02/23. Second forecast high water is 08:45 on 22/02/23. All times are local and refer to the high water time at Avonmouth. Plan driving routes to coastal roads, which may be flooded. Please be careful along beaches, promenades and coastal footpaths and roads. We expect flooding to affect the tidal River Avon from Sea Mills to Conham in Bristol and between the Avonmouth Bridge and Shirehampton Park including Pill and Shirehampton. We are closely monitoring the situation. Our incident response staff are closing flood gates. This message will be updated Wednesday 22/02/23, or as the situation changes.

Sourve: gov.uk

[Red Squirrel]

Looks like a couple of trains were cancelled this morning; all appears back to normal now according to Realtime Trains...

Update: gwr.com says normal service after 13.00. Looks like they may be making use of the CFN^▸ (Clifton Down station) turnback.

[DaveHarries]

Looks like a couple of trains were cancelled this morning; all appears back to normal now according to Realtime Trains...

Update: gwr.com says normal service after 13.00. Looks like they may be making use of the CFN^▸ (Clifton Down station) turnback.

Not quite: my parents went off to Oxford for the day and found, when they got back into Temple Meads at about 1630, that they could not get a train to Sea Mills because the bridge there was being checked over.

They obviously opened the line at some point because 2K54 (1810 Weston-s-Mare - Severn Beach) got through to Severn Beach but its return 2K57 (2001 Severn Beach - Bristol Temple Meads) is, as at 2130 still at Avonmouth from which it should have departed at 2010! The line is again closed from Shirehampton to Clifton Down as I write this and the Clifton Down turnback is again in use. Screenshot attached from OpenTrainTimes.

Online sources give tide as being due at 14.08m @ 2108hrs.

Dave

Edit @ 2210hrs: Just come back from Sea Mills where I noted that the high water mark was only about 1ft above the section of path that runs under the bridge on the station side. High tide forecast at 14.28m @ 0926 for Thursday morning (23rd February) according to https://www.tidetimes.org.uk/port-of-bristol-avonmouth-tide-times-20230223

[Red Squirrel]

GWR^▸ (Great Western Railway) are running a shuttle service between BRI^» (Bristol Temple Meads - next trains) and CFN^▸ (Clifton Down station) this morning, at approx 26 min intervals.

[Red Squirrel]

I had a look under the viaduct at Sea Mills on the weekend. Presumably these girders are supposed to brace it during high tides. I can see why NR^» (Network Rail - home page) might be a bit worried!

[brooklea]

I had a look under the viaduct at Sea Mills on the weekend. Presumably these girders are supposed to brace it during high tides. I can see why NR^» (Network Rail - home page) might be a bit worried!

Looks pretty ‘non-structural’ to me!

[Red Squirrel]

Looks pretty ‘non-structural’ to me!

Especially the bit stuck in the mud in the foreground...

[froome]

Indeed. I've stated here before my fear each time I've walked under the bridge following the Avon Walkway path on the mudflats, as there is much corrosion evident all around. If you are in a train, you obviously don't see the state of the pillars, so travel completely unaware.

Presumably as a first measure, NR^» (Network Rail - home page) could install a speed limit over the bridge, but would that help at all?

If not, any work to the bridge would obviously mean the closure of the line beyond Sea Mills (and possibly beyond Clifton Down, as would Sea Mills be able to act as a station with works so close by?). It would be ironic if that happened on the day Portway Parkway opened!

[Red Squirrel]

Indeed. I've stated here before my fear each time I've walked under the bridge following the Avon Walkway path on the mudflats, as there is much corrosion evident all around. If you are in a train, you obviously don't see the state of the pillars, so travel completely unaware.

Presumably as a first measure, NR^» (Network Rail - home page) could install a speed limit over the bridge, but would that help at all?

If not, any work to the bridge would obviously mean the closure of the line beyond Sea Mills (and possibly beyond Clifton Down, as would Sea Mills be able to act as a station with works so close by?). It would be ironic if that happened on the day Portway Parkway opened!

I am not a signaller, but my understanding is that (without some sort of pilot working) trains can only be turned back at Clifton Down and Avonmouth.

My assumption is that the bracing girders were added some time after the bridge was originally constructed. As such, they could presumably be replaced if (and it may be a big 'if') the columns are in a reasonable state. From the look of the girders, it would possibly be better to remove them to prevent damage to the columns when they inevitably collapse.

[Mark A]

Seamills, the bridges, from across the river. Photo from 2008.

Mark

[Red Squirrel]

This picture, taken around 1963, shows the girders in a better state. I wonder if they've been painted since?


Gillett's Crossing from Bristol, United Kingdom, CC BY 2.0 <https://creativecommons.org/licenses/by/2.0>, via Wikimedia Commons

[Western Pathfinder]

Considerably less load bearing mud back in the day !
With regard to speed restrictions for the use of the bridge,as it happens all services departing Sea Mills in the direction of Shirehampton ,acceleration to line speed takes place after crossing the structure and those in the direction of Clifton have already slowed to station approach speed before the bridge.

[ellendune]

The load that a column can take is partly determined by it slenderness (broadly ratio of height to width). If this ratio is high then the column can buckle under load.  The effective height of the column can be reduced by installing cross members. This is most elegantly shown in the 'scissor arches' under the tower of Wells Cathedral.

I presume, therefore, that these steel cross members were installed to strengthen the columns.  It may be that if the only traffic is DMUs^▸ (Diesel Multiple Unit) these are not needed any more (I assume the freight goes via Henbury).  However they would be fairly simple to replace. 

[TonyK]

Indeed. I've stated here before my fear each time I've walked under the bridge following the Avon Walkway path on the mudflats, as there is much corrosion evident all around. If you are in a train, you obviously don't see the state of the pillars, so travel completely unaware.

Presumably as a first measure, NR^» (Network Rail - home page) could install a speed limit over the bridge, but would that help at all?

I seem to recall a 5mph limit over the bridge, that being some 10 years ago.

It may be that if the only traffic is DMUs^▸ (Diesel Multiple Unit) these are not needed any more (I assume the freight goes via Henbury).   

The rubbish trains between Brentford and Sita arrive loaded via Henbury, but the empty trains return via the Severn Beach line. I assume that saves a change of direction at Hallen Marsh when more lightly loaded - but still heavy.

Looks pretty ‘non-structural’ to me!

It is now.

[johnneyw]

A Facebook page for the Beach Line reports that services seem to be suspended at present due to high tides.  There a couple of pictures of the bridge over the confluence of the river Trym with the Avon where the water level isn't that far short of the track.
Another website showing arrival and departures at Montpelier for the line is showing no services at present either...which is curious as services could surely still turn back at Clifton Down Station, giving a partial service?


Edit:  It's just dawned on me that there's RMT^▸ (National Union of Rail, Maritime & Transport Workers) industrial action today.....flood tide came at a helpful time in that case!