I don't know the answer, but the box looks too immaculate to be an operational one on network Rail, so I think it's on a preserved line.  I do know that the GWSR was in use today because I saw an engine in steam at Cheltenham Racecourse station, so I'll guess Toddington or maybe Winchcombe on GWSR.

Blue Anchor signal box, West Somerset Railway?

Ingrow?

Yep Williton. Asked if I could pop up to the box after trains were out of section and bobby had completed his duties. He had 90 minutes before next train. I have been in this box before but can't find the photos. When I was here previously there were fewer levers in use. Today there are 24, with 23 in use. Two further levers to the side for crossing gates interlock.



I did a drone flight here filming two trains passing. All the staff were friendly and genuinely interested in the drone footage. No concerns about what I was going to do after I explained my flight plan, competence and insurance. Whenever possible, as a courtesy, I'll inform anyone who may have concerns about a drone.

Later, at another location I didn't have such a friendly interaction. I've detailed that in my 'Stations from the air' thread available to established forum members.

Maybe our Witham Bobby can answer but what does lever 1 unlock/release?

Well, it used to be the Up Distant Signal on the end of that one.  The GW^▸ (Great Western) usually used "fixed distant" signals at passing places on single lines.  As in fixed at "caution" in order to remind drivers of the speed restriction entering the loop.  This would perhaps be 15 or 20mph.  When the Minehead Branch was upgraded in the 1930s, the pointwork at each end of the loops was laid-out for 40mph running, and automatic token exchange apparatus was installed.  So fast trains could rocket past places like Williton and Blue Anchor without having to loose much speed and time.  So, workable distant signals were installed.  If the section ahead was clear, and the token had been obtained, the signalman could load up the auto exchanger with the token and clear the signals, including the distant, and later watch the train clatter past.

When we came to re-open the line, we took the decision (encouraged by the Railways Inspectorate) to use only fixed distant signals.  With a 25mph line speed limit (or 40mph for DMUs^▸ (Diesel Multiple Unit)) there would be no time saving by having these signals workable

Now, as the picture shows, the lever is a release, for the ground frame that gives access off the Down Loop into the yard.  The shunter needing to make a move into or out of the yard will call-up the bobby and ask for a release, which enables the ground frame to be used at the location, to shift the points.  Once the release lever in the 'box is reversed, all the levers for the running signals that could lead to conflicting moves will be locked normal, so that the signals can't be cleared. 

I don't know the exact setup at Williton for this, but it's usual for the signaller reversing the release lever resulting in a key in normally locked an instrument at the ground frame to becoming released.  The key can then be inserted in a lock on the ground frame to enable its levers to be operated.  When the shunting operations are complete and the running line is again clear, and the levers in the ground frame have been set back to their usual positions, the key can be removed from the lock and put back into the instrument, the signaller advised, following which the release lever in the 'box can be restored to normal, and the running signal levers are then freed to be operated.

You'll note that the top of the lever has been cut off.  The lever is in effect a switch, needing not much effort to work.  You wouldn't want to put your weight behind it and give a big swing.  The shortness of the lever is a reminder.  Helpful in not ending up on your a*se

The signallar explained to me that many of the semaphores are motor operated now, after the signalling was upgraded. Same for the points. The furthest mechanical 'pull' from that box is 667yds to signal 20. Can't quite read the lever in my photo. I think 20 is the Down Main Distant Starter.