Did lower quadrant signals 'bounce'?

[Stubby47]

Hj all,

I'm contemplating adding a LQ signal to T-CATS, just as the upper level leaves the scene.

As I'm using servos for the points, it's not a big stretch to use one for the signal too, and it can be made to bounce if required.

 

But did they?

 

Ta

[Phil Bullock]

Oh yes ....

 

 

And they still do!

 

 

Edited September 18, 2019 by Phil Bullock
Additional info

[Stubby47]

Brilliant Phil, many thanks 

[The Stationmaster]

The simple answer is - it depends.  It depends on how good and up to spec all the various  pivots are and far more importantly how the signal is worked.  if everything is as it should be throwing the lever back hard is as likely to make the post sway as the signal arm bounce because the arm is linked to the balance weight by a substantial down rod and the balance weight is heavy enough not to bounce so any motion can be taken up by the post on a straight post signal.  I tried that one back in the 1970s with a signal directly opposite the 'box concerned which was maintained in good condition with limited wear - I couldn't get any noticeable bounce out of it but I could make the post sway a little

 

If there is slop here, there and every where and the lever is flung back hard then you can get the effect seen in those two films that Phil posted - note that both are 'modern' views of signals which are around 40+ years old.   And of course if you translate the motion to 4mm scale things are rather tiny - the signal arms in this films are 12" deep so 4mm scale they are 4mm deep.  Thus a bounce 3" either side of the normal position will only be 1mm and I reckon the Worcester signal in the second film was moving less than that out of the horizontal when it was chucked back to danger.

 

Overall I don't think bounce can be realistically portrayed on lower quadrant signals in 4mm scale because it is so slight and I'd be dubious about UQ signals even tho' in some cases the arm stop on those was sprung in order to reduce wear and damage when the arm went back to danger.

[Stubby47]

Thanks Mike.

 

So if the lever was carefully returned there would (should) be no bounce, even in an older system with wear & tear?

And if there was, it would be hard to see in 4mm anyway.

 

That will make the operation of the signal much easier.

 

Ta.

[RedgateModels]

If it helps Stu, the signal on Summat Colliery (OO by Embedded Controls) has bounce. The signals on Fourgig East (O controlled by MERG electronics) do not. I'm happy with both

[Siberian Snooper]

Plenty of lower quadrants still in use,  at Liskeard and beyond. No idea for how much longer though.

 

 

 

[rab]

11 minutes ago, Siberian Snooper said:

Plenty of lower quadrants still in use,  at Liskeard and beyond. No idea for how much longer though.

 

 

 

From what I remember, the semaphores west of Liskeard are like prisoners on death row, theyre under threat but  still living.

[Phil Bullock]

1 hour ago, rab said:

From what I remember, the semaphores west of Liskeard are like prisoners on death row, theyre under threat but  still living.

 

Same with the Worcester ones - allegedly that dastardly Mr Stationmaster once tried to pronounce the death sentence but they are still there.....

[The Stationmaster]

14 hours ago, Phil Bullock said:

 

Same with the Worcester ones - allegedly that dastardly Mr Stationmaster once tried to pronounce the death sentence but they are still there.....

A clear need to correct you Mr Phil.  I tried once in my BR days and some work was actually done on the ground but the scheme (Stage 1 of the whole lot) was subsequently cancelled due to the funds being diverted elsewhere.  I subsequently had two other goes - the second of those really being more part of the Worcester Parkway proposals than anything else -  during my time working for a consultancy concern.

 

Thus far on the ground the only part of any of my three attempts which has actually been implemented is part of the re-doubling of the OWW which I looked at as far east as Honeybourne or thereabouts and even then they haven't done the re-doubling to Parkway which I suggested as part of one of my timetable offerings (for a shuttle service from Parkway to at least Foregate Street).  I've still got the basic S&T outline plan for my original effort back in the 1980s. 

[Phil Bullock]

Cheers Mr S! I stand admonished....

 

remains to be seen how parkway will work, your scheme sounds far too sensible to be built in at the start.... but time may tell....

[PenrithBeacon]

I have seen video of GW lower quadrant signals being returned to horizontal, no bounce but the post swayed about quite a lot.

[jim.snowdon]

On 18 September 2019 at 12:04, Stubby47 said:

Thanks Mike.

 

So if the lever was carefully returned there would (should) be no bounce, even in an older system with wear & tear?

And if there was, it would be hard to see in 4mm anyway.

 

That will make the operation of the signal much easier.

 

Ta.

Correct, for both lower and upper quadrant signals.

 

Jim

[eastglosmog]

I have seen some wartime videos which include signal arms being returned to danger.  One of an LNER upper quadrant signal shows extreme bounce - several inches by the look of it.  However, it was a promotional film about women working on the railway and I suspect it was done for effect and not normal practice.  Another one on the SR at Salisbury taken to show USA S160's at work, shows no bounce whatever as the lower quadrant arm is returned to danger at a steady pace.

[bécasse]

1 hour ago, eastglosmog said:

I have seen some wartime videos which include signal arms being returned to danger.  Another one on the SR at Salisbury taken to show USA S160's at work, shows no bounce whatever as the lower quadrant arm is returned to danger at a steady pace.

One would have expected signal arms on the Southern at Salisbury to move at a steady pace. The signals of both East and West boxes were pneumatically worked (although East box was subsequently converted to electro-pneumatic operation, I am not sure now whether this was pre- or post-WWII). Both boxes had slides rather than levers, and certainly the ones in the East box required a considerable knack to pull or push back without getting caught by the locks.