British Aircrew Mk4, Mk4A and Mk4B Life Jackets
The Mk4, Mk4A and Mk4B life jackets follow the same principal design of waistcoat and stole as the Mk3 life jacket, however, the pockets are re-designed to accomodate different equipment.
In the main they were manufactured by Beaufort / Frankenstein, however, one example at the bottom of this page reveals that they were not the only manufacturer used.
Mk4 Life Jacket
The Mk4 saw the introduction of the SARAH radio / beacon equipment, and new McMurdo sea activated cell and lamp. On previous jackets the buttons had been sewn on, but the Mk4 introduced slotted buttons mounted with tape, a method still in use today.
Mk4A Life Jacket
The Mk4A was an improverment on the Mk4 by changes to how the SARAH pockets are fastened closed. This previously had been done using cord treaded through eyelets in a complex manner, but the Mk4A changed this to nylon draw-rods and tape loops. An additional improvement was the long white straps on the battery pocket, which is one of the main visual differences.
Mk4B Life Jacket
The Mk4B was similar to the Mk4A, but was equipped with two-piece SARBE radio / beacon equipment installed. The Mk4B was also provided with a pocket for Miniflare distress signals.
(Note: The SARAH battery, beacon and speach untis and all the leads are described in AP2554C.)
Service Images
Mk4A Life Jackets - Victor B2
The two white stripes on the SARAH beacon battery pouch make the Mk4A life jacket instantly recognisable.
This image is intersting as it shows two configurations of Mk4A life jacket. The airman on the left has the older style of survival pack lowering line attachment, while the other two have the latter suggesting a mix of front and rear crew members in shot as the rear seats are different to the front ejection seats.
For am image that appears in multiple places on the internet, little is published of its origins or the date / location it was taken. This copy of it is watermarked from the Imperial War Museum, but I can't find it in their archives.
Mk4A Life Jackets - Lightning F1A 56sqn Firebirds
Again, easily identifyble as Mk4A jackets by the white stripes on the SARAH beacon battery pocket.
The mid airman's jacket shows the latter survival pack lowering line attachment fitted to the left hand lanyard, the two other lanyards on the right hand side have no fittings attached. This airman also looks as though his jacket may have suffered from a Fluorescein dye marker leakage on the right side stole container.
Image source unknown, credit will be given - please get in touch.
RAF / RN Resources - Mk4 Life Jacket
AP1182E Vol 1, Section 2, Chapter 8, Fig 1, AL58 October 1955
AP1182E Vol 1, Section 2, Chapter 8, Fig 2, AL58 October 1955
Fig 2 ilustrates how the Mk4 pockets are closed with lacing, which is the main detail superceded by the Mk4A.
I have found the components of the Mk4 life jacket listed in two AL's of AP1182E, with some differences:
AP1182E Vol 1, Section 2, Chapter 8, Paragraph 2, AL58 October 1955
Quote:
Stores Ref. Nomenclature 22C/1480 Waistcoat 22C/1182 Stole 6D/1624 Operating head, Type M 6D/1623 CO2 cylinder, 34 gr. 22C/1185 Fluorescine sea marker 22C/**** Life line 250 lb. and toggle 22C/1186 Whistle 27H/2733 Ground/air emergency code 27H/2107 Heliograph 2 in. x 2 in.
AP1182E Vol 1, Section 2, Chapter 8, AL90 October 1962
8 years later some of the stores ref numbers for the Mk4 life jacket have changed. Also worth noting that AL90 of the chapter quotes the Mk4 life jacket assembly as 22C/1480 (previously the waitcoat ref no.), and the waistcoat is now under 22C/1479.
Quote:
Ref. No. Nomenclature 22C/1479 Waistcoat, Mk4 22C/1182 Stole 6D/1624 Operating head, Type M 5A/4216 Lamp, Type B 5J/3411 Battery, sea activated 27C/2366 Ground air emergency code card 22C/1185 Fluorescine sea marker 22C/1186 Whistle 22C/1739 Life line 250 lb. 27H/2107 Heliograph
AP1086, Book 7, Section 22C, Second Edition, AL212, 14th January 1965
AP1086, the stores reference number listing from 1965 details the Mk4 life jacket under Stores Ref No. 22C/1480, and it's components as:
Quote:
Nomenclature Detail Cylinder, gas, carbon dioxide, aircrew life-jacket assembly 34 grammes. Reference 6D/9432080 Fluorescine, sea markers Ref. No. 1185 Head, operating, Type M Reference 6D/1624 Label, groud/air emergency code Reference 27C/2366 Lamp, life-jacket C/w skull cap. See Reference 5A/4216 Stole, gas-inflated C/w oral inflation valve. Ref. No. 1182 and Ref. No. 1186 Waistcoat, Mark 4 Incorporating Ref. No. 1739
RAF / RN Resources - Mk4A Life Jacket
AP1182E Vol 1, Section 2, Chapter 8, Fig 8, AL100 October 1963
Fig 8 below illustrates the nylon draw-rod pocket fastening system introduced to the Mk4A life jacket, replacing the eyelet lacing method used on the Mk4.
AP1182E Vol 1, Section 2, Chapter 8, AL100 October 1963
AL100 of this chapter quotes the Mk4A life jacket assembly as stores ref. no. 22C/1877, and the Mk4A waistcoat under 22C/1876.
Quote:
Description
12. All the components of the fully equipped life jacket are the same as those of the MK. 4 jacket except the waistcoat which is the Mk4A provisioned under Ref. No. 22C/1876.13. The Mk4A waistcoat differs from the Mk4 in the following respects:-
(1) The beacon flap and speech unit are secured in the closed position by nylon draw rods which are passed through beckets fitted to the flap and pocket. The draw rods are fitted with finger rings to facilitate withdrawal. At the bottom of the speech unit pocket is a press stud provided to retain the finger ring in position.
(2) Longer buckle chapes are fitted on the battery pocket so that the wearer can more easily release the webbing straps by sliding the buckles down the front of the pocket to disengage the straps.
(3) A larger flap has been fitted for housing the battery/beacon cable.
Manufacturers Resources
Beaufort (Air-Sea) Equipment Ltd., Leaflet ME3/1, date unknown
This brochure covers the Mk4A and Mk4B (as well as the Mk6, 6A and 7). This first quote states the fabric colour as traffic yellow.
Colour
The lifejackets are normally manufactured in traffic yellow colour for easy location of a survivor, but other colours can be supplied to customers requirements.
Radio Location Equipment
Pockets are provided on the lifejacket for holding radio location equipment:
Mk. 4A - 3 piece SARAH
Mk. 4B - 2 piece SARBE
Exhibits
Life Jacket Mk4A 1968 - RAF Wildenrath
I was lucky to have this Beaufort Frankenstein made Mk4A life preserver donated to my collection by a fellow collector. It has had it's Fluorescein dye pocket removed unfortunately, but this may have been to do with it being used for wet-drill practice at the end if it's service within the RAF.
Here we look at some of the aspects in detail, however, the SARAH beacon is missing so pockets have been filled with foam rubber to give them form, and household electrical wire used to represent the speech unit wire.
I have installed the latter style of survival pack lowering line attachmet to the left hand lanyard, as per the 56 sqn Lightning image above.
Beaufort / Frankenstein label:
Detailed shot of the closure buttons shows the tape mounting as opposed to being traditionally sewn on.
The distintive two white straps ("buckle chapes") of the Mk4A life jacket over the SARAH battery pocket:
The nylon draw rod introduced for the Mk4A life jacket is visible here holding closed the SARAH beacon speech unit pocket. Also pulled out of the pockets are the lamp and whistle:
CO2 release head connected to the stole, the 34g CO2 bottle is a replica item I made to fill the pocket. Also the red thread and household Blu-Tack putty is representative of what would have originally been a lead seal:
Oral stole inflation tube pulled out of its retaining "hood" for the photograph. The vale inside is opened for inflation / deflation by depressing the end of the mouth-piece against an internal spring:
Life Jacket Mk4A - Industrial Leather Products Ltd.
This Mk4A turned up in South Africa, and is the only example I've seen made by a different manufacturer to Beufort / Frankenstein Ltd, instead this example was made by Industrial Leather Products Ltd, of Horley, Surrey, UK.
Image with thanks to Dean Wingrin of www.saairforce.co.za
