While waiting for that (hopefully) revealing document and plans from the National Archives, I have returned to the puzzle of the main mast and its access point.
The handle that wasn't (Chapter 5) turned out to be an access panel of some sort, but it is very firmly bolted in place on the other side of that partition....
And while examining it (photographically) from the side next to the mast, I noticed an interesting feature on the mast itself .... right opposite that sealed panel.
I have asked Simon to examine this area and find out whether it is a reinforcement ring around an access hole, or a sealing plate covering a possible access hole. History relates that:
"There were two openings in the mainmast, one below the deck and another on the level of the lantern when hoisted up. Inside the mast was a ladder which the lamplighters climbed to trim the lamps. Both openings were stiffened round the edges with wrought iron frames".
Now if that is a stiffening ring around an access point, why is the access close to a bulkhead instead of further round the mast in a clear area? If it was an unavoidable choice, perhaps that sealed panel gave access to the access. But sealing the access would suggest that access was no longer required and this in turn would suggest that the old moveable (oil) lamp was no longer in use and wick-trimming no longer needed. So perhaps when the Belfast Harbour Commissioners converted her to a Pilot Station, they changed the lamp to the fixed (electric) variety - as seen in the 1954 photo of the vessel - using the original mast but sealing up all the access points.
Mind you, I am still puzzled by the differences in hull shape and proportions as set out in Chapter 6. You can see why I am impatient to see those documents from the National Archives!
Meanwhile, another historical feature to be preserved are the anchor-chain 'nostrils' (what is the nautical term?) at the bow, on either side of the forward access hatch.