Another "Barbel"-like innovation was the combination of the conning tower, control room, and attack center in one space. This was continued in all subsequent US nuclear submarines. Combining the functions in one space was facilitated by the adoption of "push-button" ballast control, another feature of "Albacore". Previous designs had routed the trim system piping through the control room, where the valves were manually operated. The "push-button" system used hydraulic operators on each valve, remotely electrically operated (actually via toggle switches) from the control room. This greatly conserved control room space and reduced the time required to conduct trim operations. The overall layout made coordination of the weapons and ship control systems easier during combat operations.