TM 5-5420-278-100019 000019 00-7SITE REQUIREMENTS AND LAYOUTS (Contd)a. For a free launch of IRB bays, the following requirements must be met:(1) The maximum river bank slope is 20%.(2) The maximum bank height is 60 in. (152 cm). (3) Water velocity should not be greater than 8 ft (2.44 m) per second.(4) The minimum water depth must be a least 6 ft (1.8 m) to free launchthe interior bay from the maximum river bank slope of 20% (This isbased on a zero bank height with the CBT backed into the water up tothe top of its rear axle hubs). (5) The minimum water depth must be at least 9 ft (2.7 m) to free launchthe ramp bay from the maximum river bank slope of 20% (This is basedon a zero bank height with the CBT backed into the water up to the topof its rear axle tire rims).(6) The minimum water depth must be at least 7 ft 4 in. (2.2 m) to freelaunch the interior bay and 12 ft (3.7 m) to free launch the ramp bayfrom the maximum bank height of 60 in. (152 cm) and river bank slopeof 20%.b. For a controlled launch of IRB bays, the following requirements must be met.(1) The maximum river bank slope is 20%.(2) Zero bank height is required.(3) Water velocity should not be greater than 5 ft (1.53 m) per second.(4) The minimum water depth must be at least 6 ft (1.8 m) for IRB-R and3 ft 7 in. (1.1 m) for IRB-I to perform a controlled launch at themaximum river bank slope of 20%. (This is based on a zero bank heightwith the CBT backed into the water up to the top of its rear axle hubsfor interior bays, and up to the top of its rear axle tire rims for rampbays.)AT MAXIMUM 5 FT (1.53 M) BANKHEIGHT THE MINIMUM WATER DEPTH IS:12 FT (3.7 M) FOR IRB-R7 FT 4 IN. (2.2 M) FOR IRB-IFREE LAUNCHSLOPE 0–20%BANK HEIGHT0–5 FT (1.53 M)9 FT (2.7 M) MINIMUM, IRB-R6 FT (1.8 M) MINIMUM, IRB-IVEHICLE MUST BE BACKED INTO WATERSLOPE 0–20%WATER DEPTH 6 FT (1.8 M) MINIMUM, IRB-R3 FT 7 IN. (1.1 M) MINIMUM, IRB-ICONTROLLED LAUNCH