A searchlight story......

[LNERGE]

The fault was with the green side proving. This probably explains why it didn't manifest itself til later in the evening. Not much chance of a green before that<g>

 

We managed to get the pony wheels of the Fowler off the road at Arlesey yesterday evening. That was an interesting 90 mins. It would have been a lot longer if it wasn't for a six wheel drive ex WW2 American tank recovery vehicle..

[uax6]

But quicker if you hadn't had a belly full!

 

That signal is so nice that it has the proper loc cabinet with it.... its one signal I'd love to give a home to.... (one can't have enough searchlights, even though the Mrs thinks you can!)

 

Andy G

[LNERGE]

Here's my latest (mechanical) searchlight..

 

 

 

 

 

I have been told these are the parts of Up Main intermediate block distant from Great Chesterford, the last mechanical searchlight used on the national network. 

 

https://www.flickr.com/photos/billatkinson2/6972305782/

 

https://www.flickr.com/photos/52087249@N07/8534856766/

 

https://www.flickr.com/photos/52087249@N07/8533738889/

Edited June 26, 2017 by LNERGE

[uax6]

That is nice, I love the LNER on the back of the lamp case. I see theres no spectacle plate with it, but I'm sure you have at least one in stock.

 

Andy G

[LNERGE]

That is nice, I love the LNER on the back of the lamp case. I see theres no spectacle plate with it, but I'm sure you have at least one in stock.

 

Andy G

I will have the spectacle plate for this one in due course. it was with the bearing/backshade and i had Mrs LNERGE's car. I do have three others anyway. Besides there's a distant banner repeater acquired today also.

[uax6]

I've been busy making up a relay set to get the searchlight and the hernia working as a pair. It sounds quite easy but the list of requirements are quite a lot:

1. to give a couple of different clearing types (ie red to green, red to yellow to green, red to yellow)
2. to drop the green aspect of the hernia back to yellow after the train has passed the distant, but before the searchlight drops back.
3. to drop the searchlight back after the train passes it.
4. to provide 6v for the searchlight mech
5. to run on either 12v or 50v, depending on the requirements of the relay set.
6. to be switchable to allow the input to be either from the auto equipment or from a lever frame.

The first thing to do was to see what I had in stock. I found a GPO 2000 type relayset can that had been stripped, a 25 point uniselector, and various 3000 type relays.

 

One thing that I haven't found so far is a 32 way shelf jack for the u-points on the relay set. Has anyone got one they can spare please?

 

Andy G

[uax6]

So here's the GPO relay set can that I found:

 

It was a standard relay only can, so it needed modifying to take a uniselector, so five minutes with a grinder produced a big hole. I welded some bits back to the can to form the mountings for the uni too. I also welded a short length of DIN rail in at the top...

 

I then got out the relays and the uniselector:

 

As they were all secondhand they needed the tags cleaning up. From:

to:

 

The DIN rail at the top was for mounting some RS timing relays. Here two are fitted, these are to become the timers that drop the signals back to yellow (hernia) and red (searchlight):

 

Five relays fitted:

 

Wiring started:

 

Now as the hernia's aspect is controlled from the 'off normal' proving contacts in the searchlight head (which detect when the yellow or green is detected, the contacts being worked off the moving vane inside the head) there is a short period of 'release' when the head swings from the yellow aspect to the green one. This short period would be enough to cause the hernia control relay to release, which would cause the signal to go green - yellow - green. To prevent this, the proving contacts in the searchlight will operate a slugged relay, and this will control the hernia relay. Here is the slugged relay:

 

This relay has a 1 inch heel end copper slug, which, when the relay operates is ineffective, but when the relay coil is de-energised, the flux in the coil is opposed by the slug , which makes the relay slow releasing, which is perfect for this purpose.

Here it is next to a normal coil:

 

Here is the relay set as it stands at the minute. Its all wired, apart from the u-points, 6v power board and one more RS relay required for the uniselector pulsing circuit. Note the large paper capacitor and resistor, part of the spark quench circuit for the uniselector.

 

Andy G

 

 

 

[beast66606]

On 01/08/2016 at 20:59, uax6 said:

I don't think the IB was removed, just the head changed for something newer...

 

Does anyone happen to have any photos of these IB's please? I'd like a numberplate to suit....

 

Andy G

 

@uax6 Andy,

 

I've grabbed this screen shot from a film about the Dereham line which continues towards Norwich, I believe this is Wymondham Down IB lever No.34 - not sure how useful, or relevant, it is but I thought of this thread while watching the film. No number plate, only the IB plate.