Hairy Bear
Member
It's the stability of the embankment. Slightly reduced over the years.
How many electrically powered trains are actually going to be using the slow lines through Sharnbrook Tunnel? If no regular passenger trains are using it are there going to be any electric freight locos using it?
or indeed the MML is linked electrically to the rest of the network for Freight to make straight on moves rather than reversing / run round moves.Until the wires stretch somewhere useful north of Market Harborough - None.
You got more chance on a charter.After my question, about which lines the Corby services use, I did the trip today. (My first leisure trip since lockdowns started) and enjoyed it.
One day I'll get to ride though Sharnbrook tunnel.
On the return trip towards London, having to cross from the fast to slows for Bedford station and back to the fasts, must be a signalling nightmare.
Not recently, but "never say never". Here's the diagram for Bedford North in about 1966, which shows the eastern pair going north as Goods lines.
Track Diagram: Bedford North (c1966) (signalbox.org)
Most of the MML was so designated when constructed, but parts were converted to passenger use (becoming Slow lines) over the years, particularly at the London end when commuting started to become more significant. Starting with West Hampstead in about 1980, progressive re-signallings have upgraded almost all Goods lines to passenger standard, but may in the Trent control area remained as Goods until the most recent re-signalling.
Passenger trains are able to use Goods lines under special arrangements. These have varied over the years but typically include clipping of any facing points that aren't fitted with locks, and a ban on permissive block working. There are accident reports on Railways Archive indicating that the permissive arrangements allowed the Midland Goods lines were jammed on occasion with successions of trains nose to tail, and managing this sort of congestion when there were far fewer passenger trains than today was a good reason to designate most of the eastern pair as Goods lines.They may have been designated as goods lines, but I remember going through the tunnel one weekday on a down semi-fast around 1966 on a diversion (I have no idea why) and several times in the early 70s, once on the up one weekday in c 1972 caused by something coming off the road on the fasts, IIRC.
In addition, if the up Thames-Clyde was running c 20 -25 mins late off Nottingham, the 17.10 ex-Derby (which, unusually, did not precede the TC into Leicester, but was timetabled after it at Trent), would be given the road off Leicester to Glendon Nth Jcn, where it would switch to the slow, ,sometimes returning to the fasts at Kettering Sth, sometimes going all the way to Bedford. to allow the TC to overtake.
There were also Sunday diversions over the slows. I can't swear to it, but I think the line speed was 50mph back then.
Post #26 indicated that the eastern pair of tracks were only goods lines as far north as Kettering Junction (where the Cambridge line came in and there were crossovers from fast to slow lines).Passenger trains are able to use Goods lines under special arrangements. These have varied over the years but typically include clipping of any facing points that aren't fitted with locks, and a ban on permissive block working. There are accident reports on Railways Archive indicating that the permissive arrangements allowed the Midland Goods lines were jammed on occasion with successions of trains nose to tail, and managing this sort of congestion when there were far fewer passenger trains than today was a good reason to designate most of the eastern pair as Goods lines.
There were other sections that became Slow lines much earlier than those immediately north of Bedford. I imagine the eastern pair between Glendon and Kettering were always permitted for passenger use, otherwise a train to or from the Corby line couldn't have taken the obvious route through the Slow line platforms. This diagram confirms that was the case in 1960.
Track Diagram: Kettering North (1960) (signalbox.org)
After my question, about which lines the Corby services use, I did the trip today. (My first leisure trip since lockdowns started) and enjoyed it.
One day I'll get to ride though Sharnbrook tunnel.
On the return trip towards London, having to cross from the fast to slows for Bedford station and back to the fasts, must be a signalling nightmare.
Thank you Kite159. I managed to do Sharnbrook tunnel in the north direction today. Another tickBit short notice but next Saturday it might be possible to do the tunnel as the half hourly Corby electrics are being cut back to Wellingborough platform 3 due to Market Harborough being closed (Nottingham/Sheffield trains are going via Corby reversing at Leicester)
Realtime Trains | Departures from Wellingborough all day on 19/06/2021
Train information at Wellingborough all day on 19/06/2021. From Realtime Trains, an independent source of train running info for Great Britain.www.realtimetrains.co.uk
So what was the point of electrifying the slows then? It’s not as if there’s electric freight going to use them, and the current 222s and future 810s can run on diesel if they have to use the slows when there’s blocks on the fasts.You'll lose 9 mins using the slows North of Bedford. So that's not really an option. I'm sure the tracks will be replaced eventually for a more faster and comfortable ride on the slows.
So what was the point of electrifying the slows then? It’s not as if there’s electric freight going to use them, and the current 222s and future 810s can run on diesel if they have to use the slows when there’s blocks on the fasts.
Everyone can be an armchair signaller now there’s on-train wifi, RTT and Traksy…
On a St Pancras - Sheffield this afternoon (non-stop to Leicester) and the 222 was going like the clappers, two early approaching Wellingborough. Unfortunately by then it had caught the preceding Connect service and subsequently ran under cautions until just south of Kettering when the 360s switched on the slow. By the time the 222 passed Kettering it was slightly late and ran like that through to Derby. Between Bedford and Kettering there was nothing at all on the slows, either down or up.
it’s bizarre that lots of money has been spent reinstating the 4th line through Sharnbrook and Wellingborough and on towards Kettering, reinstating platforms, electrifying it all, and yet most of the 360s run on the fasts while some of the long-distance 125mph expresses are held back. Why aren’t the Connect services run on the slows north of Bedford - wasn’t that what they were electrified for?
So what was the point of electrifying the slows then? It’s not as if there’s electric freight going to use them, and the current 222s and future 810s can run on diesel if they have to use the slows when there’s blocks on the fasts.
Yes this seems to be a common issue with the new timetable. What I find surprising is that more of the connects aren’t crossed the slows at Wellingborough North. This would save a lot of time, as the crossover is 50mph, and the train is accelerating away from Wellingborough.
Instead most are crossed at Kettering South and have to slow down from 110mph to 30mph, so the following Sheffield catches up. Any time advantage of 110mph on the fasts versus 90mph on the slows is also lost.
Surely the answer to get things moving is upgrade the slows. Or Change the timings to the slow line. I cannot figure why a new timetable has issues after 20 or 30 billion spent on the railway.
When I was in Japan I was on a train which stopped and they parked it on the slow for 5 mins to let a fast go by and then we went behind the fast train. Why do we not adopt this?
On a St Pancras - Sheffield this afternoon (non-stop to Leicester) and the 222 was going like the clappers, two early approaching Wellingborough. Unfortunately by then it had caught the preceding Connect service and subsequently ran under cautions until just south of Kettering when the 360s switched on the slow. By the time the 222 passed Kettering it was slightly late and ran like that through to Derby. Between Bedford and Kettering there was nothing at all on the slows, either down or up.
A lot of the Corbys are departing Wellingborough at the same time as an Up train's approaching Wellingborough, and when there isn't one you'll sometimes find there's a freight booked on the down slow.
It's not unusual for an Up Connect service to be diverted on the slows from Wellingborough if there's a late running longer distance one, but more unusual for a down one to do the same, though it does happen.
I think the correct timetable's far from ideal and needs a good look at, headways between Wellingborough and Kettering are sometimes less than they should be, but there's no simple solutions with the stopping patterns as they are. Crossing some onto the slow line at Sharnbrook might be a better option, there's fewer clashes with Up trains and they'd lose less time overall, but it would still mean some turn arounds at Corby would be shorter than they should be, and runs with risk of conflicts with freights on the slows.
After reading your post I had a quick look on Traksy to see why a down fast couldn't be switched to the down slow south of Wellingborough into platform 3. It appears there's one crossover missing from the layout to allow that, which feels like a false economy to me - and one that means platform 3 will hardly ever be used.
Indeed that's what I said (on-train armchair signallers) and what I suspected in terms of the real-world challenges. The discussion around the detail is fascinating. I was obviously rather naive in assuming - as I watched the infrastructure go up - that all the money spent on electrifying the slows, adding an extra platform at Wellingborough and reinstating the additional line from Sharbrook through Wellingborough was primarily to support the EMR Connect project. To me, the upgrading of the slows seems to be a bit of a waste based on current utilisation and the reticence to use it.Everybody can be an armchair signaller now, especially when looking at one problem, but looking at the big picture usually means things are a lot more complicated.
I had a quick look on Traksy to see why a down fast couldn't be switched to the down slow south of Wellingborough into platform 3. It appears there's one crossover missing from the layout to allow that
That’s all valid of course, it just seems like the current timetable makes poor use of the infrastructure. Hopefully it’s something that will be tweaked and finessed.
I suppose the issue with crossing at Sharnbrook is that the trains are once again slowed from 110mph to negotiate a 20mph crossover. Also means effectively there will then be no opportunity for 360s to exceed 100mph north of Bedford, because you’re lucky to reach it between Wellingborough snd Kettering.
I’d say the low speed of the crossovers relative to the linespeed is a major impediment of the MML as a whole, as we see south of Bedford when EMR expresses are checked down behind thameslinks crossing over at Harpenden and Radlett junctions (40mph max).
Since the timetable change there also seems to be a lot more congestion around Bedford. Double blocking on the up fast is common, with EMR services again being checked down from 125mph to a crawl only for the signal to ping off to green (often with nothing crossing at Bedford south, and nothing being followed).
Admittedly the intercities are usually a few minutes ahead by Bedford, so this doesn’t necessarily translate into a late arrival into London, but it’s frustrating nonetheless.
Thinking about the whole issue, this is still a bit of a transitional phase,
- i.e. the timetable has only had a couple of months in the real world so perhaps we will see some tweaking?
- the 222s will be replaced and presumably electric 810s will have a bit more acceleration which both increases the chances of catching a 360, but also helps recovery when that happens.
- Presumably the 360s are limited to 100 South of Bedford?
From recollection of posts by better-informed folk on this forum, a DF -> UF crossover was omitted due issues around space and track curvature between the Nene bridge and the UF -> DS crossing.
This is a nonsense - the slow lines have been re-laid in large part to make it 4 track throughout. This really, really should have include upgrading the slows for higher speeds. Up Corby services should be able to run all the way to Bedford on the slows. Granted, the down service is more complex given the need to cross the up fast.The Up trains often do this at Wellingborough, standing in Platform 3 or 4 waiting for an express through 2.
To upgrade the slows further you need more money, and even then you won't eliminate the issue of having to cross the up fast to get there without even more money for a flyover, and then you won't get rid of the problem of freights in the Wellingborough area.