Bomb Dropping on Mirror

[pete-c]

The above description of practice flights from Eastchurch appear in an Instructor's logbook during 1916.  Has anyone else come across this?  Could this refer to a 'Sound Mirror' - the first of which I believe was constructed in 1915?   All these flights were relatively short - 12 to 20 minutes duration so, whatever, and wherever the target was, it wasn't very far from Eastchurch.

[MerchantOldSalt]

Pete

GU's logbooks mention "mirror practice" on several occasions.  I believe it was a ground support device whereby a mirror was laid on the ground in which the bombing aircraft was reflected, the plane sent a wireless signal to simulate a bomb dropped and by consulting the position of the plane in the reflection it could be worked out if the simulated bomb would have hit the target or not.  How it worked exactly I do not quite understand but I'm sure somebody knows!

Tony

[pete-c]

Cheers Tony.  I've actually just come across a reference on the Kingston Aviation website to 'bomb dropping practice with mirrors' at Coudekerque, in July 1916, but it is stated that this is thought to refer to a periscope bombsight.

[MaxD]

https://theromneymarsh.net/soundmirrors#timeline suggests the Maidstone, Hythe, Fan Bay, Joss Gap 1915/1917 are likely for 15 mins out and back from Eastchurch.

 

Max

[pete-c]

It seems as though Tony's reply may be nearer the truth.  Just found this: 

 

https://discovery.nationalarchives.gov.uk/details/r/C3202682

 

it would be good to see some diagrams.

 

EDIT: IWM have an image (Q 73738) showing a 'spotting mirror for bomb dropping' on HMS Vindex.   Possibly the same sort as used at Eastchurch?

Edited 3 February , 2020 by pete-c

[MikeMeech]

On 03/02/2020 at 14:42, pete-c said:

The above description of practice flights from Eastchurch appear in an Instructor's logbook during 1916.  Has anyone else come across this?  Could this refer to a 'Sound Mirror' - the first of which I believe was constructed in 1915?   All these flights were relatively short - 12 to 20 minutes duration so, whatever, and wherever the target was, it wasn't very far from Eastchurch.

Hi

The 'Handbook of Aircraft Armament' of the Admiralty, Air Department, 1916, has drawings and details of the 'Bomb Dropping Mirror' as used in training. (The Naval & Military Press have even reprinted this publication).  This was on the majority of Naval Air Stations at the time. One of the drawings of the device is below.

 

Mike

[Jon_B]

It was a Batchelor Mirror. My great-uncle also records 'mirror practice' in his logbook during his RNAS bombing course in early 1918.

 

Description (including the drawing above) in this thesis on the History and Development of Aircraft Instruments 1909 - 1919, free online: https://spiral.imperial.ac.uk/bitstream/10044/1/8266/1/John_Kirkham_Bradley-1994-PhD-Thesis.pdf

 

Jon

 

[pete-c]

Mike and Jon - many thanks for your replies.

 

Mike, shortly after your reply was posted I was in receipt of the very same illustration via another source.  It seems that this instrument was the brainchild of Flight Lieut. T.A. Batchelor R.N. and Lieut. H.E. Wimperis, R.N.V.R. - the first examples being put to use in October 1915 and, as Jon suggests in his post, they may well have been still in use at the end of the war. 

 

Jon, many thanks for the link - fascinating stuff indeed!

 

 

[Guest]

My first post here. Hello!

 

I attach a couple of pages from the Log Book that has the 'Mirror' references in the OP's post. The 'Mirror' is referred to in over 200 flights within the Log Book. The flights were in a Farman and spanned a period of eighteen months. The height flown was usually between 1,000 and 2,000 feet. Each flight was about twenty minutes in duration.

 

The pilot was Flight Sub Lt C Tollemache.

 

The advantages of this device were numerous in my view. For instance:

 

1. No requirement to return and rearm with practice bombs.

 

2. No loss or damage to practice bombs.

 

3. Bomb target could be located almost anywhere as there was no danger of injury or damage to property from falling bombs.

 

There are probably more.

 

We do not know how accurate it was. There appears to have been no allowance for wind drift on the bomb, but perhaps at 2,000 feet or less this factor would not have been a problem?