Weird formation on the Liverpool St to Enfield/Cheshunt line

[Matt D]

Hello,

I live in a house in N16 that overlooks the Liverpool St to Enfield/Cheshunt line, just past the bridge that crosses Stamford Hill next to Stoke Newington station. For at least a couple of weeks now, there have been regular passes along the line by a weird-sounding consist, sometimes several times a night, in both directions.

The main confusing point is that the formation is clearly diesel powered, possibly at both ends (the LST-Enfield/Cheshunt line is electrified with overhead catenary wires), is very short (only a few vehicles long, including engine/s), and seems to contain a vehicle that is creating a loud blowing or sucking noise in the middle.

Annoyingly, I have been unable to see this odd train, as we have a very tall fence that blocks the view of the line on the ground floor. I can hear it perfectly well (it is as loud as all hell), but by the time I have scrambled upstairs on the occasions when i am home during the daytime, it has already passed. During the day, the trees between us and the track and the darkness make it impossible to make out.

Does anyone out there have any experience of what this peculiar train might be?

Cheers,

Matt D

[52D]

I think there is a leaf blower out and about.

[Matt D]

Ah. That'd be it.



I meant 'during the night' earlier, by the way. It's obviously not dark during the day.

[Mickey]

Deleted

[manna]

G'Day Gents

It is obviously cheaper to run these trains all night than cut the trees down, or would that upset the tree huggers, !! I do like trees, but not around railway lines.

manna

[StevieG]

These trains, as seen in the Home counties on the ECML, and Micky and Matt D's cited workings, are formed of two or three 'freight' vehicles (known as FEA's - any wagon TOPS-code experts out there?), top 'n tailed by two class 66s.

[CVR1865]

Showing my Modern image nerdiness: FEA, Flat, container flat, version E (there will have been an FAA,FBA etc in the past, designed at least) A for Air brake.

Thanks
Simon

[Mickey]

Deleted

[Bryan]

The Sandite is only laid at specific points of low adhesion which may not actually be on the route traversed by the freights.
A number of the RHTT (Rail Head Treatment Trains) work out of York Daily / Nightly and cover a rather large slice of Yorkshire.
One spot I know of is on the Up approaching York Station from the Scarborough line near Marygate / Bootham The train has to run out to Strensall crossover and run back to York to lay Sandite on a 100yd stretch.
Scroll down about 2 paragrahs.
http://www.railsigns.co.uk/sect23page1/sect23page1.html

As for the Water jetting train.
The purpose of that is to blast off the leaf residue from the rail. Again though this will be in areas of Low adhesion. But may be on gradients such as from Leeds to Headingley (I did a cabride in a Pacer up there once and the driver had great difficulty in notching up due to slipping)
Think of it like your garden path. The rail doesn't clear the green mould off does it which is why so many people buy pressure washers to clean up their paths.

http://www.railsigns.co.uk/sect17page1/sect17page1.html

[swhite01]

As noted the service is probably the Railhead Treatment Train (RHTT). The location you describe is probably served by Broxbourne and will comprise top and tail class 66's with 2 or 3 water carrier/jetting units. This link http://www.flickr.com/photos/8336963@N0 ... 1989598786 shows the ECML GN service at Watton at Stone last week. I can post the timings of the Broxbourne workings if of interest.

[Matt D]

Thanks to everyone for responding. I finally caught a glimpse of the elusive train travelling in the direction of Liverpool St this morning and it was indeed the RHTT, as swhite01 and several others suggested. It was under the stewardship of two claret and gold EWS-liveried 66s, with 66 172 at the 'down' end and a similar unidentified sister at the 'up' end.

Incidentally, seeing these two engines on such a short formation made me wonder how efficient this is. Does anyone know if running a pair of 66s like this is still cheaper than, for example, a pair of 20s, 31s, 37s or 47s? I imagine that the engine in a 66 is considerably more efficient than the units in the earlier BR designs, but they are massively overpowered for the job and even taking higher maintenance into account, the fuel costs must be fairly eye-watering. Are there any figures available to show that running a pair of big, modern diesels in this situation is cheaper, or is it is just the ubiquitousness of the 66 that gets it the gig?

Also, would there be a case for someone running a small fleet of newer, less powerful engines for lighter tasks?

[Danby Wiske]

is it is just the ubiquitousness of the 66 that gets it the gig?

Also, would there be a case for someone running a small fleet of newer, less powerful engines for lighter tasks?

"Ubiquitousness" hits the nail on the head I think. With modern traffic patterns, the lighter tasks you mention would be so few and far between that it simply wouldn't be worth supplying (and maintaining) a fleet of smaller engines.

That's progress for you!

[Bryan]

The reason for the 2 locos is the amount of reversals probably required on the route.
In some cases the RHTT is run as an MPV with demountable tanks but with a limited supply of these vehicles, Tank wagons and top and tailing is required.
http://en.wikipedia.org/wiki/British_Rail_MPV

[cambois]

I saw a RHTT topped & tailed with a pair of 20s going south through Church Fenton on Monday. Thought there was enough water about without adding to it!!

[Matt D]

I understand the operational limitations that require that the trains should be 'top and tailed'. It is presumably quicker for the driver or crew to swap trains than to run the train round, and run-round loops will not always be available anyway, so you need an engine at either end so you can change direction at the end of the stretch of line that you are clearing. I'm guessing that it also provides redundancy, as since both engines are running when they travel past, but they are only being operated from one end, if one engine failed you could still operate the whole train from the other engine in one unit (like a miniature freight HST set).

I'm guessing that this extra flexibility and security is why nuclear flask trains trains are similarly top-and-tailed.

What I was getting at was that a pair of 66s is clearly massive overkill for such light work. I was wondering whether the train was operated by a pair of 66s simply because that was all that was available, or because despite being more powerful, the 66s were cheaper to run than a pair of lighter but less efficient earlier BR engines. Cambois' and Danby Wiske's observations would suggest it was the former. This would also explain why Hunslet-Barclay retained some 20s to power the weedkilling trains.