C stock door gear

[d7666]

A few months ago I changed job and often go to The Site Thou Shalt Not Name in the W12 postcode area.

This means I now travel on C stock regularly. I have noticed on a smaller proportion of travel the door gear has quite an explosive burst of air when doors are operated, while a larger proportion do not, the biggest sound being the mechanical clunking.

Are there door gear differences in the C fleet ? I bet this has been asked before or someone will point me to an obvious reference, but I've not managed to find one yet.

--
Nick

[Colin]

There are most certainly differences - pretty much a decades worth!!

The C stock is made up of C69 (the majority, with the 69 bit giving a clue to their introduction date) and C77 (the minority, built later on).

The C69's are built to imperial measurements, whilst the C77's are built to Metric. There are also differences noticeable to the driver in the cab. They can be coupled in any combination though and you are therefore highly likley to came across a mix of the two builds running together.

So in essence, if there is indeed a difference in door speeds, my money would be on the 77's being the faster ones.

If I've remembered the C stock numbering correctly:

55xx/56xx DM's & 65xx/66xx Trailers are the C69's
57xx DM's and 67xx Trailers are the C77's

[d7666]

Oh yes LOL I forgot about there being C69 and C77 builds.

However, its not door speeds I am refering to, it is the *sound* from the door gear.

But I'll try an remember to look at car numbers.

--
Nick

[Deleted]

I don't want to derail the thread, but

Jul 3, 2009 19:07:17 GMT Colin said:

The C69's are built to imperial measurements, whilst the C77's are built to Metric.

what does that mean in the terms of different behaviour (or something like that, don't exactly know what word I'm looking for)

[prjb]

If memory serves, the 77's have different door valves and thats why they produce a distinctive sound when they close.

[Dstock7080]

Jul 3, 2009 20:38:20 GMT prjb said:

If memory serves, the 77's have different door valves and thats why they produce a distinctive sound when they close.

I thought there were changed to one standard upon refurb?

[d7666]

Jul 3, 2009 20:30:00 GMT @eirikho said:

I don't want to derail the thread, but

Jul 3, 2009 19:07:17 GMT Colin said:

The C69's are built to imperial measurements, whilst the C77's are built to Metric.

what does that mean in the terms of different behaviour (or something like that, don't exactly know what word I'm looking for)

;D

Feel free to digress; I do it enough myself

I had completely overlooked there are C69 and there are C77 - and as its the first I'd heard of imperial and metric measurements so guess thats as interesting as door gear.

--
Nick

[towerman]

You'll probably find the noise on closing is the silencer missing on the door valve exhaust.

[prjb]

Jul 3, 2009 21:12:36 GMT Dstock7080 said:

Jul 3, 2009 20:38:20 GMT prjb said:

If memory serves, the 77's have different door valves and thats why they produce a distinctive sound when they close.

I thought there were changed to one standard upon refurb?

Possibly, yes? I have been away from 'C' stock for a while now (too long in fact) and I stand to be corrected.

Ask me about 'S' Stock!!

_{I'll probably mess that answer up too!! ;D}

[Deleted]

Jul 3, 2009 19:07:17 GMT Colin said:

The C69's are built to imperial measurements, whilst the C77's are built to Metric.

According to Steam to Silver, "the general arrangement drawings of this stock have been set out in metric units for the first time". The book was published in 1970, so it would have been referring to the C69 stock.

Did they design in metric and build in imperial?

[slugabed]

Jul 4, 2009 2:24:24 GMT @sydneynick said:

Jul 3, 2009 19:07:17 GMT Colin said:

The C69's are built to imperial measurements, whilst the C77's are built to Metric.

According to Steam to Silver, "the general arrangement drawings of this stock have been set out in metric units for the first time". The book was published in 1970, so it would have been referring to the C69 stock.

Did they design in metric and build in imperial?

Probably the other way round,subject to the following.....
In other fields,at least,the process of "metrication" consisted of a junior member of drawing-room staff taking each design drawing,rubbing out the Imperial measurements and replacing them with millimetres.This worked as long as everyone did it,and did it consistantly.
Problems arose in terms of converting tolerances,and when manufacturers took the whole thing far too seriously,say phasing out the production of 1" (25,4mm) widgets to be replaced by 25mm versions which NO LONGER FIT!
After metrication,all subsequent drawings would be metric both in mearsure and in scale,and many old drawings would be re-drawn in metric scale,although the basis for the dimensions may be Imperial.
And,of course,many designers still "thought" in Imperial,then converted at the drawing stage.

[Colin]

Jul 3, 2009 19:12:13 GMT d7666 said:

However, its not door speeds I am refering to, it is the *sound* from the door gear.

Ah, I misunderstood your OP

Jul 3, 2009 20:30:00 GMT @eirikho said:

I don't want to derail the thread, but

Jul 3, 2009 19:07:17 GMT Colin said:

The C69's are built to imperial measurements, whilst the C77's are built to Metric.

what does that mean in the terms of different behaviour (or something like that, don't exactly know what word I'm looking for)

I thought it would help to show that the two builds are quite different - just a bit of trivia really.

Jul 4, 2009 2:24:24 GMT @sydneynick said:

According to Steam to Silver, "the general arrangement drawings of this stock have been set out in metric units for the first time". The book was published in 1970, so it would have been referring to the C69 stock.

Did they design in metric and build in imperial?

My fellow admin 'Solidbond' did my stock training on the C stocks, and it was him that told me the C69's were built to imperial whilst the C77's were built to metric.

[tubeprune]

As built, the C96s had the old Peters type of pneumatic latch door valves while the C77s had Schraeder spool valves. I don't know if that's still the case. Can anyone confirm?

[Deleted]

Jul 4, 2009 13:12:08 GMT tubeprune said:

C96s

;D

[d7666]

When I made the original posting I had completely overlooked that there were C69 and C77 stocks.

However, since the responses pointed this out, I have been looking at car numbers - and I can say that the door gear noise I am referring to is present in the smaller proportion of cars on *both* C69 and C77.

Further, I have noticed at least one car made the explosive air noise on one side but not the other ... my travel is Baker St - ShepBushMark so get both sides working because of islands at Edgware Road / Paddington / RoyalOak.

I am wondering then is it possible there was originally different door gear on C69 and C77 but its [maybe ?] interchangeable and has got swapped around during the 30-40 life so far of the stock and/or swapped around at refurblement ?

Or, perhaps Towermans' suggestion about unsilenced door gear exhaust is correct ?

--
Nick

[100andthirty]

both train now have the same type of door valve. All have slilencers on the exhaust side. some of the silencers are more effective than others; perhaps they've been bought at different times and from different suppliers

[Deleted]

When I last rode the Hammersmith & City line, the doors on the train I was on seemed to be very reluctant to close. The train also seemed to be unusually noisy when the doors were open, and there was also a faint but detectable smell of fumes at some of the stations.