than the pressure applied to the opposite side of the piston lower pressure on one side prevents the sudden application of force and sudden movement which might cause possible collapse of the tank apparatus for towing and travel of the tank apparatus the brace members are disposed in aligned abutting relation with no hydraulic pressure in the actuators fig6 shows the front hydraulic actuator 39 extended to raise tongue or yoke 58 into its upward position tongue 58 is pivotal with the outer pipe 70 which is rotatable relative to a stationary inner cross member 72 and which is welded to the i beams 32 34 through which it extends via openings provided cross member 72 may typically be 5 u2033 in diameter and the outer pipe 70 may be 6 u2033 in diameter the outer pipe 70 is rotatable with the tongue or yoke 58 to move the yoke upwardly and downwardly the cross member 72 is mounted in openings in opposite i beam members and is a cross member of the frame comprising the heavy i beam members 32 34 the arrangement of components shown in fig5 and 5 a including an outer pipe rotatable relative to a fixed rod pivoting arrangement etc enables multiple functions by a relatively simplified combination and arrangement the rod or pipe 72 which is a cross member of the frame is secured between i beam members 32 34 as shown the yoke 58 is mounted on the pipe 70 to rotate therewith between its upward position of fig6 and 7 and its downward position of fig5 the relatively simplified arrangement provided by the invention eliminates or reduces component deflection and the assembly serves essentially three functions rather than.