The full Geek in my cellar.

https://flic.kr/p/FJK5pt

Most impressive - the machining and steam engine bits are presumably at home, and the things with HV grading rings and a gantry crane are presumably work related - if not I'm envious as well.
Mike.

Thank you Mike  Yes the big stuff is my day job with industrial electron accelerators up to 3MeV, The very big stuff was a visit to the Diamond Light source as part of a radiation safety traing course.

This is the hobby stuff in action, a 12cc petrol injected twin cylinder engine undergoing some load trials:

https://youtu.be/7RVp_fwLo0o?si=o75XRC3gcp8_d4Zf

One advantage of incandescent bulb traffic lights is that they are much better at melting any snow which has accumulated on or around the lens.

I do feel like I've entered a bit of a time warp here, basically don't panic - all these issues were very thoroughly worked through around 20 years ago...probably longer in the highways world.

And yes, where applicable railway LED signals (or more accurately their control and monitoring functions) are SIL4.

I do remember one of my my colleagues in the early 2000s saying that LEDs could never work in rail signalling but he was a) a mechanical engineer and b) rather thoroughly proved wrong.

Cheers,

Andy

(formally UK Engineering Manager / Product Manager for (amongst other things) incandescent rail signals for a major manufacturer...delighted that that part of the role is now obsolete) 

wallywombat said:

One advantage of incandescent bulb traffic lights is that they are much better at melting any snow which has accumulated on or around the lens.

P.S. On this point, the person I mention above did also, quite correctly, regularly point out that the problem is that road traffic lights are the wrong way up! The problem doesn't arise with rail signals (at least as far as snow blocking the red signal which is the important bit).

Funny how when a subject comes up it immediately pops up again...I was helping a colleague with their CEng application this morning, and one of their bits of evidence is that they led a team who developed from scratch a rail signalling interlocking system in Turkey. We were looking for an example of consideration of sustainability, and they pointed out that they had introduced a new feedback and monitoring and control system in their interlocking logic to allow the use of low energy LED signals, including the safe detection of failures. I did smile at the coincidence that I'd only just written about that, not having thought about it at all for several years...