A Community Devoted to the Preservation and Practice of Celestial Navigation and Other Methods of Traditional Wayfinding
From: David Pike
Date: 2018 Jul 11, 02:09 -0700
Do you know what sextant was fitted into our Avro Vulcan B2, as ours has been taken out and hole/s plated over, before we received it. Do you have any images I could use to show to people in the Vulcan, when I am giving my tours, what it looked like and how it was used. I would be very grateful for any help in my quest. Stephanie Lawton
If your Vulcan has plates over the sextant mounting holes it’s possibly because in museum service the mountings tend to leak and cause maintenance problems to the airframe. You might find them stored away in a cupboard somewhere.
I’m not sure about the Vulcan BMk1, but the BMk1a and B2, including your XJ823, had either a Smiths Kelvin Hughes (SKH) Mk 2 or Mk2b sextant depending upon which happened to be currently fitted. The SKH Mk2 sextant had a bubble reference (and you had to make your own bubble), and the SKH Mk2b had a pendulous reference, with a graticule which was always present so long as power was applied and the sextant wound up. I never saw a SKH Mk 2a (a 2b with a swivel eyepiece); a 2c (a later version of a 2a) or a 2T ((Twilight) a Mk2 fitted with polarising filters to obtain heading checks in polar regions) in a Vulcan.
The Vulcan had to have two sextant mountings, one port and one starboard, because the pilot’s blister, which also contained the life-raft, sat directly over the front of the rear crew compartment. Enthusiastic crews could draw a second sextant before a celestial sortie so that they didn’t have to keep moving the sextant from port to starboard during 7-shot sandwich fixing, That meant you could get the fix over sooner. Given the choice, most navigators would choose a Mk2b, because you didn’t have to keep fiddling to achieve your ideal bubble.
I can send you as many photos of a SKH Mk2b plus the mounting as you wish if you contact me privately. However, I can also tell you where your museum can buy a working SKH Mk2a, which is almost indistinguishable from a Mk2b, for £60+VAT+£14p&p. Last time I checked, the owner still had eleven to get rid of. I’ve been keeping it to myself, because they’re not much use without the mounting, and I was hoping the price might come down further. If too many people try to buy one, he'll keep the price high. DaveP Vulcan Navigator 1969-80