The Technical File | Groundforce Groundforce Shorco | Technical File Issue 3.0 GF Double Acting Manhole Brace The GF Double Acting Manhole Brace range consists of a series of hydraulically adjustable legs which, when assembled together, form a mid-range bracing system to support square or rectangular excavation sizes from 2.0m to 6.0m in length. The range consists of 4 individual legs types designated A to D, each incorporating a double acting hydraulic ram unit, which provides up to 1.0m of on-site length adjustment. Features / Benefits Single 50mm diameter corner pin connection for rapid assembly on site. Ideal for light to medium duty load applications in 4-sided excavations. The legs can to be both expanded and retracted hydraulically by a hand pump to aid installation and removal. Double acting legs incorporate a lock-off valve for greater security and allow the pump hoses to be easily released and reconnected without fluid loss. Compatibility Can be used in conjunction with the MAXI Brace system with suitable adapter shoes. See Section 3.3 (Brace Ancillaries) for more details on frame combinations. Technical Specification Outer Sleeve: 180x180x10 SHS grade S355 (50C) steel. Inner Sleeve: 150x150x12.5 SHS grade S355 (50C) steel. Working Moment Capacities (based on outer sleeve) - 83kNm. Hydraulic Ram Specification: Double acting, steel construction 83mm bore x 1000mm stroke rated axial load capacity = 150kN (FOS 2:1). 1.2.1