Here are the tech specs as sourced from II CORPS documents.
7.2 Inch T40 Rocket Launcher:
Weight of Launcher: 5,500lbs empty,6,700lbs
fully loaded
Tubes: (20) 90-inch tubes, 2 rows of 10
Tube Material: Sheet steel
Life of Tubes: Indefinite
Firing Method: Electrical, single-shot or ripple
fire
Maximum Firing Rate: 20 rounds in 10 seconds
(ripple fire)
Muzzle Velocity: 160 feet per second.
Maximum Range: 230 Yards
Effective Range: Typically 60-75 Yards
Rocket Type: 7.2 Inch High Explosive Rocket T37
Rocket Dimensions: 61 lbs, 35 inches long
with circular fins
Explosive Charge: 32 lbs of C2 plastic explosive
Laying on Target: By turret gun sight
Traverse and Elevation: Traverse by turret,
elevation by main gun.
Main Gun Operation: Can be fired with
launcher installed
Jettison Capability: Hydraulically .
jettisoned in seconds
Armor Plating: Will divert up to .30 caliber
bullet
4.5 Inch T34 Rocket Launcher (Standard 60-Tube Unit):
Weight of Launcher: 1840lbs empty, 4240lbs fully
loaded
Tubes: (60) 90-inch tubes, 2 rows of 18 on top,
launcher installed 2 rows of 12 on bottom
Tube Material: Plastic
Life of Tubes: Begin breaking up after 4 salvos,
average life 15 to 20 salvos
Firing Method: Electrical, single-shot or ripple
fire
Maximum Firing Rate: 60 rounds in 30 seconds
(ripple fire)
Muzzle Velocity: 850 feet per second
Maximum Range: 4,600 Yards
Effective Range: 3,900 Yards
Rocket Type: 4.5 Inch Aircraft Rocket with
(ripple fire)
Rocket Dimensions: 40 lbs, 33 inches long,
fin-stabilized
Weight of projectile in flight: 15.25 Lbs
Rocket Flame: 30 to 40 feet
Explosive Charge: 4.3 lbs of TNT explosive
Conventional Blast Equivalent: 105mm shell
Laying on Target: By turret gun sight
Traverse and Elevation: Traverse by turret,
elevation by main gun
Main Gun Operation: Cannot be fired until
launcher is jettisoned
Jettison Capability: Hydraulically
jettisoned in seconds
Armor plating: None
It took a crew of five up to two hours to reload and reconnect electrical wires. Also as shown above, they could launch single rockets or some combination (or all) of rockets for a sequenced or full "ripple launch". Most of these tubes actually came off combat aircraft.
The other key points I highlighted. Previous references from earlier posts might help, to include the War Dept. film from the You Tube ref.
http://www.tanks-encyclopedia.com/ww2/US/M4_Sherman.php
Regards,
Pat