12 carriage 450 to Poole?

[antharro]

In this thread it was stated that 12 carriages of a 450 could fit into platforms at Poole, although the 12 carriage Poole services split at Southampton. I was under the impression that there wasn't enough power available south of Bournemouth to handle trains of that length - hence the 442s and 444s splitting at Bournemouth. Am I correct or has something changed?

 

[bigdelboy]

In this thread it was stated that 12 carriages of a 450 could fit into platforms at Poole, although the 12 carriage Poole services split at Southampton. I was under the impression that there wasn't enough power available south of Bournemouth to handle trains of that length - hence the 442s and 444s splitting at Bournemouth. Am I correct or has something changed?

I think "south of bournemouth" comes from the traditional point of transition from electric to diesel. ( I think I'd use "west" rather than "south" myself)

There obviously has to be enough juice to get units from bournemouth to branksome, about 1/2 way to poole, so they can get to bournemouth depot.

Also at least in the past some 12 car rush hour services started from poole, at least in the early 442 days nearly 30 years ago.

 

[swt_passenger]

In this thread it was stated that 12 carriages of a 450 could fit into platforms at Poole, although the 12 carriage Poole services split at Southampton. I was under the impression that there wasn't enough power available south of Bournemouth to handle trains of that length - hence the 442s and 444s splitting at Bournemouth. Am I correct or has something changed?

No, the declared issues with power limits are 'west of Poole'. 10 car 442s always ran as far as Poole in the peaks, as do some 10 car 444s now. The main reason the majority of splitting and joining takes place at Bournemouth is because the track layout there is designed specifically for that, with the two middle sidings immediately west of the station.

 

[Abpj17]

No, the declared issues with power limits are 'west of Poole'. 10 car 442s always ran as far as Poole in the peaks, as do some 10 car 444s now. The main reason the majority of splitting and joining takes place at Bournemouth is because the track layout there is designed specifically for that, with the two middle sidings immediately west of the station.

I went through there the other day, and would agree with this. Poole is a relatively small station - two lines only; thinly staffed. Bournemouth has more lines, sidings, more platform staff etc. to help provide flexibility for this.

 

[Lrd]

No, the declared issues with power limits are 'west of Poole'. 10 car 442s always ran as far as Poole in the peaks, as do some 10 car 444s now. The main reason the majority of splitting and joining takes place at Bournemouth is because the track layout there is designed specifically for that, with the two middle sidings immediately west of the station.

Do you think the curvature of the track at Poole may have been an issue for the coupling/uncoupling as well?

 

[swt_passenger]

Do you think the curvature of the track at Poole may have been an issue for the coupling/uncoupling as well?

A fair point as well (as reliability of joining on curves is crucial), but I'd expect the rationale when the 442s arrived was more likely to be just that the REP/TC split was already happening at Bournemouth, and that's probably where the logical demand split was, and that was what people were quite used to already.

So, I doubt there was much debate, I reckon they just kept the splitting/joining point the same as they were already doing, and there's been no need to change yet.

 

[bigdelboy]

At Poole the down half appears near straight; whilst the up half is quite curved. I think mechanically for joining would be just about ok as i think the joining pair would be just in line (for 5+5 444's)

However IMHO all the logistics point to a joins/splits normally at bournemouth.

 

[Matt Taylor]

The down side at Poole is far from straight, it is an utter nightmare trying to safely despatch even an eight car from that platform.

 

[D7666]

ITYF Poole is unsuitable for attaching and detaching long trains not because of curvature and sighting - after all Lewes is a good deal more curved than Poole, and Faversham is not straight either, nor even Bournemouth down side, and so on, but because of signalling.

To split a 12 car you need a lot longer platform inside signals than dead 12 cars which Poole is because IIRC the front will SPAD if it moves forward on detach (?? because of some rule that I don't fully understand about not having the road for a split, because while splitting such a train is not ready ?? **) and the back bit can't move back because of concerns about level crossing which would have to be closed for road traffic. Likewise attaching you need Calling On and I don't think they have that at Poole. OK maybe 10x442 might fit attach / detach but 12x450 would not. Even if I am wrong about detaching, you'd only routinely deach where you attach, and there is no Call On, so it's a non runner anyway.

** both Tunbridge Wells Central (station) and St Albans (centre siding) have restrictions on detaching for similar reasons. Tunbridge Wells the platform can accomodate 12x375 but to either reverse complete train or attach/detach IIMU it is limited to 11x375. St Albans siding is 8car long for reverse but unable to split to 2 x 4car not enough room to split and not SPAD. The one working (in old GoVia days) that use to split at St.Albans Down direction, was split on the Down SLow, one portion reversed in siding, the other portion ECS to Harpenden Junctions and cross to Up slow there to come back. all to not have the road set out of the siding during the split.

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Nick
--- old post above --- --- new post below ---
On the power side IIMU the issue is with Moreton substation (and I'm not sure if this means a rail sub or a grid sub) and lack of feed from grid. At least that is how it was before the half hourly service started. I suggest this is resolved now, as the current draw of a AC motor unit is very different and overall higher than DC motor units like Reps and 44s) but long trains don't go there because there is no need. I also suggest though of the basic Weymouth service were still hourly not half hourly then you would see routing 10.444 there.

--
Nick

 

[TEW]

There were some issues with the third rail between Wareham and Weymouth one day earlier this year which meant that a 5-car was at risk of gapping. The solution was to run hourly 10-car 444s to Weymouth instead. It went on for a whole afternoon.

 

[antharro]

Yeah, I should've known longer trains could have run to at least Parkstone for the depot. So I could have guessed they would run to Poole too.

Ta for the replies.

I remember hearing that it was a limitation on the amount of current available overall, so it doesn't surprise me to hear that 10x444 has run to Weymouth - I would assume that the limit would be on the amount of current available overall, not on the current available to one specific train.

I did not know 10x442 ran to Poole regularly though, or 10x444.