Wireless Telegraphy and the
defeat of the U-Boat

Early Holland class submarine
1914-1918
"The Admiralty are not prepared to take
any steps in regards to submarines,
because this vessel is the weapon of the
weaker nation. If, however, this vessel can
be rendered practical, the nation which
possesses it will cease to be weak, and
will became really powerful. More than
any other nation we should have to fear
the attack of submarines."
George Goschen, First Lord of the Admiralty, 1900
Naval Aircraft
HMA 1”Mayfly”
Wrecked before its first flight
Discouraged further development
Wireless
Within two years of
Jacksons experiments
Wireless telegraphy was
institutionalised into the
Royal Navy
HMS Defiance Torpedo school
Submarines Sunk
Ships which survived
Detection: Room 40 and the
Y intercept stations
December 1914: Room 40 well informed
about the strength and general location of
the U-boat Fleet
May 1915: Room 40 was able to follow the
track of a U-boat across the North Sea.
Excellent intelligence on German submarines expected to
be in the area sometimes including the submarines ID
number and even the name of the captain.
F. Thorpe
Convoys
“During the whole war,
except for a single occasion,
... , no ship escorted by an
airship was ever sunk.”
Abbott (1989) p.4)
“Long range wireless signalling was essential to the effective control of a
convoy, its main function being to provide a means by which a convoy could
be diverted so as to avoid a locality in which enemy submarines were
operating, …”
Review of Trade position, Sept 1917
Co-ordinated Attack
16th Sept 1918
SSZ.1 on patrol
Spotted an Oil Spill and followed the track
Called patrol boats to support which
dropped depth charges on the target area
destroying UB.103
29th Sept 1918
R.29 on patrol off the Northumberland Coast.
Spotted an oil patch on the water and signalled
a nearby destroyer HMS Ouse to join the attack.
A second destroyer HMS Star also joined the
attack sinking UB.115
Types of airborne Wireless
Transmitters and Receivers
Transmitters
Receivers
Type 12 Aircraft Set
Type T
Type Ta
Type Tb
Type Tc
Type Td
Type 50
Type 51
Type 52 – 40 watts
Type 53 – 500 watts
Type 54a – 200 watts
Type 54b – 100 watts
Air Mechanic F. Thorpe
Wireless operator on airships and
flying boats Based at RNAS Calshot
and RNAS Cranwell
The radio equipment in the Cranwell
airships consisted of, [...], a type TC
crystal receiver with a Brown’s Relay
amplifier and a type 52B spark
transmitter.
The equipment of a wireless operator
going on patrol ... included ... a close
fitting leather helmet with attached
brown’s adjustable diaphragm
earphones, a large, accurate and
The radio equipment of the Calshot
waterproof patrol issue watch, an 8cell
flying-boats consisted of a thermionic
fully charged lead-acid accumulator, ...
valve receiver and a type 52B spark
, a lead weighted code book, and an
transmitter.
Aldis lamp.
Conclusions:
The defeat of the U-boat threat in the First World War relied on a variety of
technologies; some new some slightly older, combined with a new tactical
approach.
•The use of aircraft as reconnaissance and weapons platforms
•The introduction of Convoys
•The use of W/T to re-rout convoys round suspected U-boat positions
•The use of W/T to co-ordinate attacks between ships and aircraft
However
There is still an enormous amount of research to be conducted on this topic.
•Following the War the efforts and results achieved by Room 40 were
downplayed in order to hide the advances made in wireless direction finding
and British Code Breaking.
•The Admiralty also downplayed the significance of the U-boat threat, not
wishing to reveal how successful unrestricted submarine warfare was or how
close it had come to defeating the Royal Navy.
Marconi wireless operators often stayed at their posts
transmitting and receiving messages even under fire.
John McMillan: Wireless
operator S.S. Wayfarer
March 1915
The safety of the ship was
“due to the promptness
with which wireless
enabled her to summon
assistance.”
Wireless room on a Cunard Liner