Alaska Class authorized in 1940, commissioned 1945, carried nine 12"/50 guns ; weighed 27,500 tons ; was 808 feet ; with speed of 33 knots.
The battle cruisers, Alaska, (CB-1) and Guam ,(CB-2), were
intended to be "cruiser killers" to outgun the Japanese 8" cruiser with a larger ship, yet was still be smaller,
faster and cheaper than a full sized battleship. The thinking was to use them as convoy escorts to defeat expected raids by Japanese
heavy cruisers. The Japanese never used their cruisers as convoy raiders. The Germans had, and British battleships had to escort high value
convoys . Those used were old battleships too slow for fleet duty, but with the weight of shell to keep raiders away from merchant ships.
The battle cruiser as a class had not fared well in WWI
where, on the battle line, they were shown to be more vulnerable to damage than a battleship and without sufficient weight of
broadside to sink enemy battleships. As an extra-heavy cruiser, they have been fast enough to chase down and to outgun other cruisers
and to chase off marauders of the German pocket battleship type that could not risk injury far from home.
Atlantic Convoy Designations
Designation Description Usual Route
SC 177 Slow convoy (less than 8 Kn) Halifax to UK
HX 377 Fast convoy (9-13 Kn) Halifax to Liverpool
CU 74 Very Fast convoy (14Kn) CN/NY to UK Originally Curacao tankers under USN protection
O= outbound from UK
OA 226 Southern UK to Canada
OB 346 Liverpool to N or S America
OG 117 UK by way of Gibraltar
ON 307 UK to North America (Halifax)
OS 185 UK to South Atlantic (Freetown) see KMS
HA 157 Halifax to Aruba (Caribbean)
HG 117 High speed Gibraltar to UK
HK 183 High speed Galveston to Key West
SL 275 Slow convoy South Atlantic (Freetown) to UK
HG 117 High speed by way of Gibraltar
MKS 162 Med thru Gibraltar to UK (Operation Torch) Slow
MKF 57 Med to UK Fast
KMS 169 UK to Med Slow
KMF 55 UK to Med Fast
PQ 41 Iceland to Archangel,USSR ; later JW series
QP 39 From Russia ; became RA series
South Atlantic and Mediterranean convoys would often join or separate at Gibraltar.
NK 164 New York to Key West
NG 207 New York to Guantanamo (Cuba)
GK 163 Guantanamo to Key West
GN 207 Guantanamo to New York
GZ 139 Guantanamo to Panama Canal
ZG 141 Panama Canal to Guantanamo
UK. The year ends with USN actually convoying British troops on American ships escorted by battleships and aircraft carrier..
There were also regional convoys with their own convoy series. Series were not consistent.
W as first letter indicated troop convoy.
A good reference: The Website for Merchant Ships during WW2
One can easily see why so many escort ships were required.
There was never any question which side the US was on in the European conflict that began Sept 1, 1939 with the invasion of Poland. From the onset USN ships reported all Axis ships observed. These were broadcast in the clear so that British cruisers could come capture the German passenger liners and merchantmen from the Caribbean trying to return to home port.
U.S. destroyers operated on relays to report current locations and would stand by to take off passengers and crew as the Germans would scuttle their ships off the U.S. coast rather than be taken as prize of war. On Sept 3, USN organized a Neutrality Patrol to 300 miles from U.S. shores Forty reserved destroyer were recommission for scouting duty. On Sept 13 the first Neutrality Patrol set sail -- the effect was to relieve the Royal Navy from duty in American waters.
The U.S. involvement gradually escalated in 1940 as German conquered France and the Low Countries. 35 more reserve destroyers were
recommissioned. FDR promised all aid short of war. Authorization to build a two-ocean navy. German armed raider traveled to the Pacific thru Arctic waters lead by Soviet ice breaker. U.S. gives 50 restored destroyers to Britain in exchange for bases from which to patrol the Atlantic and Caribbean.
By 1941 U-boats sink ships faster than they can be replaced. Six merchant raiders were still at sea plus battleship raiders.
USN organizes support force to MOMP, Mid Ocean Meeting Point. Quarter of Pacific Fleet ordered to Atlantic on patrol expanded to 3/4 of that ocean. When Bismarck penetrates into western Atlantic
FDR orders battleships to Iceland and to shoot-on-sight any Axis ships. Combat with USN destroyers vs. U-boats; destroyer sunk. Begin transfer of escort carriers to
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About this page: convoy. Notes about the Convoy System..
Drafted Nov 28, 2004
Last updated: November 1, 2015, add convoy designations.