Splitting single-track services into multiple separate shuttles: Has this ever been considered as a way of increasing frequency?

[PTR 444]

So picture this: you have a 50 mile stretch of single track line with no passing loops and want to run an hourly interval service along it. Unfortunately, it is impossible to run a through service the whole way as an hourly service over that length would require at least two units, and it is no less than certain that they will meet head-on somewhere along the route.

But what if they met head-on at a station close to the midpoint of the line? If you did this, you could split the line halfway (similar to Ormskirk/Kirkby) and run two separate shuttles which would be timed to meet at that station at the same time. Even though passengers would have to change to get from one end of the line to the other, each shuttle would be able to run at least twice as frequent than if one unit shuttled along the entire length of the line. The connections would be guaranteed as well since the units have nothing else to conflict with.

It’s a completely random idea, but I can see some logic in it as a temporary solution for medium distance single-track lines which are too expensive to double but demand an hourly frequency, as well as lines which are longer but can sustain a slightly lower frequency. Would such an idea ever be workable here or anywhere else in the world?

 

[Bletchleyite]

Yep, there's one place it actually is done - Maidenhead to Marlow, which is run as two separate shuttles (Maidenhead to Bourne End, Bourne End to Marlow) at peak times. They don't meet end on, rather in a two platform terminus, but it's basically the same idea.

Something similar is also being proposed for the Far North Line.

 

[PTR 444]

Something similar is also being proposed for the Far North Line.

Interesting. Where abouts would it be split and what is the frequency proposed?

 

[RT4038]

So picture this: you have a 50 mile stretch of single track line with no passing loops and want to run an hourly interval service along it. Unfortunately, it is impossible to run a through service the whole way as an hourly service over that length would require at least two units, and it is no less than certain that they will meet head-on somewhere along the route.

But what if they met head-on at a station close to the midpoint of the line? If you did this, you could split the line halfway (similar to Ormskirk/Kirkby) and run two separate shuttles which would be timed to meet at that station at the same time. Even though passengers would have to change to get from one end of the line to the other, each shuttle would be able to run at least twice as frequent than if one unit shuttled along the entire length of the line. The connections would be guaranteed as well since the units have nothing else to conflict with.

It’s a completely random idea, but I can see some logic in it as a temporary solution for medium distance single-track lines which are too expensive to double but demand an hourly frequency, as well as lines which are longer but can sustain a slightly lower frequency. Would such an idea ever be workable here or anywhere else in the world?

How often are there 50 mile stretches of single track line with no passing places? This plan seems very inconvenient for through passengers merely to save on the cost of a passing loop?

 

[Bletchleyite]

Interesting. Where abouts would it be split and what is the frequency proposed?

There's a thread on it here:

Proposed new Far North Line timetable?

Just reading Modern Railways, and a letter in it refers to a proposal in a previous issue (which I must have missed) of reducing the end to end service to 2 trains per day, but running semifast, and separate local services terminating at Helmsdale. Does anyone know more about this proposal?

www.railforums.co.uk

 

[PTR 444]

How often are there 50 mile stretches of single track line with no passing places? This plan seems very inconvenient for through passengers merely to save on the cost of a passing loop?

I suppose it depends whether the increased frequency compensates for the removal of through trains all the way.

Let’s take Whitby for example, I’m sure the locals would love much more than the 6 or so trains per day they get. How about running a regular 2-hourly shuttle between Whitby and Battersby to connect with an extended Nunthorpe terminator?

Or better still, split the Whitby - Battersby section once more at Glaisdale so both portions can run hourly!

 

[RobShipway]

Isn't some of the line between Ore to Ashford International already run on a similar basis to what is being suggested?

 

[DPQ]

Isn't some of the line between Ore to Ashford International already run on a similar basis to what is being suggested?

Ore to Ashford is currently served exclusively by hourly through trains from Eastbourne.

In a pre-covid past there were also supplementary hourly Rye to Ashford shuttle services. These no longer run and are rumoured to never run again...

 

[zwk500]

The major problem with this idea is that you'd need quite long dwells at either end to make sure the shuttles overlapped, or have inconveniently long connections. It's also quite a poor utilisation of stock and crew, and requires either outstabling and carefully planned unit rotation or lengthy ECS moves at the beginning and end of the day, or the 1st/last trains extended which preventing the shuttles starting until the unit for the furthest section is clear.

If there's demand to increase capacity a loop will probably be better value over the service lifetime. Give people a choice between car and 1 train direct to city centre, they'll actually think about it. Ask people to make 2 or 3 changes with 5-10 minute connection times and they'll get in the car without a moment's hesitation.

 

[telstarbox]

Exactly right.

 

[LSWR Cavalier]

The Great Orme Tramway is in two single-track parts with a short walk between at the middle station.

 

[David Goddard]

I suppose it depends whether the increased frequency compensates for the removal of through trains all the way.

Let’s take Whitby for example, I’m sure the locals would love much more than the 6 or so trains per day they get. How about running a regular 2-hourly shuttle between Whitby and Battersby to connect with an extended Nunthorpe terminator?

Or better still, split the Whitby - Battersby section once more at Glaisdale so both portions can run hourly!

With the ability to pass trains at Battersby and Glaisdale already then there is no point in splitting the service.
Nunthorpe to Glaisdale takes about fifty minutes so you could presently run a two hourly service with trains passing there.

 

[Tomnick]

But what if they met head-on at a station close to the midpoint of the line? If you did this, you could split the line halfway (similar to Ormskirk/Kirkby) and run two separate shuttles which would be timed to meet at that station at the same time. Even though passengers would have to change to get from one end of the line to the other, each shuttle would be able to run at least twice as frequent than if one unit shuttled along the entire length of the line. The connections would be guaranteed as well since the units have nothing else to conflict with.

The thing is that you can't just have two trains meeting each other in the middle of a long single line section without some way of keeping them apart - a physical separation (with alterations to the signalling system as you now have two dead-end single lines instead of one single line section) or some form of signalling mid-section (with suitable overlaps, which would leave you with a decent walk from one train to the other!). I can't think that either option would cost much less than a proper crossing loop, especially a Penryn-style solution that doesn't involve the expense of a second platform, accessible footbridge etc..

 

[The Planner]

The thing is that you can't just have two trains meeting each other in the middle of a long single line section without some way of keeping them apart - a physical separation (with alterations to the signalling system as you now have two dead-end single lines instead of one single line section) or some form of signalling mid-section (with suitable overlaps, which would leave you with a decent walk from one train to the other!). I can't think that either option would cost much less than a proper crossing loop, especially a Penryn-style solution that doesn't involve the expense of a second platform, accessible footbridge etc..

Especially if it got designed with the overlap overlapping the other overlap!

 

[class17]

Can anyone remember how it worked when the Golf came to Lytham several years ago? A much more intense shuttle Preston to Lytham and a less intense shuttle Lytham to Blackpool South? It may have been St. Annes rather than Lytham railway station.

So it is not such 'a completely random idea' as the OP suggests.

 

[Tomnick]

Can anyone remember how it worked when the Golf came to Lytham several years ago? A much more intense shuttle Preston to Lytham and a less intense shuttle Lytham to Blackpool South? It may have been St. Annes rather than Lytham railway station.

So it is not such 'a completely random idea' as the OP suggests.

I don’t know exactly how it was done, but I’d imagine that it’d be something along the lines of working by pilotman to a point of obstruction - a sensible temporary solution on a very short term basis, but totally unsuitable for anything longer term than that.

 

[Dr Hoo]

With nothing more than a 'temporary buffer stop' (aka sleeper chained across the rails) I had heard that there was some disquiet at the lack of collision mitigation, specifically TPWS. I though that the Lytham 'expedient' had been banned afterwards.

 

[Elecman]

Can anyone remember how it worked when the Golf came to Lytham several years ago? A much more intense shuttle Preston to Lytham and a less intense shuttle Lytham to Blackpool South? It may have been St. Annes rather than Lytham railway station.

So it is not such 'a completely random idea' as the OP suggests.

The split was at Ansdell and Fairhaven not Lytham or St Anne’s