The Lt. Cdr. Frederick Maunsell Sextant

The Lt. Cdr. Frederick Maunsell Sextant


I purchased this sextant in 2007. My interest was raised when I read the inscription 'F.R.G. Maunsell, RN' engraved on the instrument. Would I be able to trace the career of the original owner?








Sextant technical description :-


The sextant has a painted brass bell-pattern frame, with a black finish and a wooden handle with a brass-lined hole for the locking mechanism. The tangent screw and clamping screw are positioned on the back of the index arm. The sextant has four green shades and three green horizon shades. Index- and horizon-glass adjustment is made by a square-headed screw, a detached key, and capped square-headed screws.

Attached to the sextant is a magnifier on a 95mm swivelling arm with a frosted glass shade. There is also a threaded telescope bracket in two parts, fitted for correcting collimation error. It has perpendicular adjustment made by a rising-piece and a milled knob. The telescope is 176 mm in length with an inverted image and four cross wires. An extra drawtube is 95 mm long with an inverted image and two parallel cross wires. A third telescope is 72 mm long with an erect image (star finder). The sight-tube is 82 mm in length and has two green shaded eyepieces, a patent greatest angle clamp screw, Heath’s patent definition shade, and a milled adjusting key. One part is missing, which is possibly a screwdriver.

The instrument is contained in a polished brass limb with inlaid silver scale from -5° to 155° by 10 arc minutes, measuring to 131°. The sextant has a silver vernier measuring to 10 arc seconds, with zero at the right.

The sextant is contained in a square fitted wooden box with a patent locking mechanism for securing the instrument when not in use. A white ivorine label on the side of the lid is marked, ‘Bell pattern Mark III sextant’. A position for a plaque on the lid of the box is empty, The lid contains a National Physical Laboratory certificate of examination, dated 5 March 1975.

Heath’s patent definition shade was to prevent the eye being dazzled during an observation in bright sunlight.


Research into career of Frederick Maunsell RN :-

A visit to the National Archives produced an extremely interesting career history for Frederick. He was a Midshipman in 1917, Sub Lieut. in 1918, Lieut. in 1920, Lieut. Cdr. in 1928 and Commander (retd.) in 1941.

Unfortunately an indiscretion over the management of the wardroom wine accounts in 1935 saw him dismissed from the Royal Navy and placed on the retired list!

However - Frederick was to redeem himself in style - with the outset of hostilities in 1939 he was re-instated and became the Skipper of HMS Speedwell (15 June 1939 to 26 February 1941). He was mentioned in despatches twice in the London Gazette in 1940 and again in 1944.


The  HMS Speedwell the citation reads as follows :-


‘Showed gallantry, skill, determination and undaunted devotion to duty during the landing of allied forces on the coast of Normandy’


I have yet to fully research the history of HMS Speedwell under Frederick’s command but I think it was very brave on his part to bounce back from his previous set back to show such bravery when it was really needed.


Here are some extracts from the history of HMS Speedwell :-


In February 1940, HMS SPEEDWELL, together with HM Ships SPHINX and SKIPJACK, was sweeping north of Kinnaird Head. SPHINX was attacked by an enemy aircraft and heavily damaged; SPEEDWELL took her in tow, and after the tow parted made repeated efforts to go alongside before the SPHINX finally sank.


SPEEDWELL took an active part in Operation 'Dynamo'  the evacuation from Dunkirk between 27 May and 4 June 1940, SPEEDWELL brought 1,668 officers and men back to England, sustaining extensive damage by enemy action in the process.


During June 1941, a ship in an Atlantic convoy SPEEDWELL was escorting was torpedoed; SPEEDWELL searched for the submarine responsible, gained a contact, and released 5 depth charges. The contact was lost twice, reobtained and further depth charges dropped, but without any visible result. As the escorts were about to conduct a second sweep, an enemy submarine was sighted surfacing. Owing to SPEEDWELL's limited speed, she did not arrive on the scene until after the enemy had been sunk by the remainder of the searching party. The submarine concerned was U651, and the entire crew, including the Commanding Office were rescued and taken prisoner.


HMS Speedwell (J87)




U651 - a Type V11C U Boat accredited with 2 ships sunk for a total of 11,639 GRT :-




I will update this page as more information becomes available through my research.