Overview

The B&G Hydraulic Ram T2 is a sealed, under-deck hydraulic linear actuator for autopilot steering systems, intended for boats with mechanical primary steering that can be back-driven. It combines the cylinder, pump, motor, clutch, and reservoir into one pre-filled unit, so there is no separate reservoir or external hydraulic hoses to route.

Hard-over time is typically 9 seconds over a 255 mm stroke (measured at 5 kg load), with intermittent operating thrust up to 700 kg. Internal relief valves are set to 62 bar to help protect the unit and its mountings during steering shocks such as rudder strikes and groundings.

RAM T2 is offered in 12V and 24V versions to match your onboard DC system. For planning cable size and protection, typical intermittent current at high load is 25 A on 12V or 12 A on 24V, and the rated ambient operating temperature range is -15 to +55 C.

Key features

• Self-contained hydraulic linear actuator with cylinder, pump, motor, clutch, and reservoir in one sealed unit
• Under-deck installation only, with mounting guidance to keep the unit above areas liable to flooding and away from heat sources
• 255 mm stroke with a typical 9 second hard-over time (at 5 kg load)
• Up to 700 kg intermittent thrust, with internal relief valves set to 62 bar for impact protection
• Back-drivable when the clutch is disengaged, so the cylinder can move with the primary steering
• 12 W clutch coil with DIN 43650 connection
• Typical intermittent current at high load: 25 A (12V) or 12 A (24V), useful for fuse and cable planning
• Uses mineral hydraulic fluid in the ISO VG10 to VG40 range; brake fluid is not suitable

Variants

This drive is offered in two voltage configurations so you can match your boat’s DC system.

Voltage is the stated difference between the variants. Selection and installation considerations still depend on your rudder geometry, mounting space, and the drive outputs available from your autopilot course computer.

• RAM-T2-12V (Voltage 12V). Suits 12V DC onboard systems, with higher current draw at heavy steering loads that makes cable routing and protection especially important.
• RAM-T2-24V (Voltage 24V). Suits 24V DC onboard systems, with lower current draw for the same steering load which can help when cable runs are long.

Compatibility and fit

The RAM T2 is specified for installations where the primary steering can be back-driven. With the clutch disengaged, the cylinder moves freely with the helm, and when the clutch is energized the course computer drives the bi-directional motor to extend and retract the ram.

Mounting is typically to a rudder quadrant or tiller arm below deck. The tiller bolt specification suits a quadrant thickness of 12 to 16 mm with a 12.2 to 12.3 mm mounting hole. The mounting foot hardware specification suits a mounting surface thickness between 12 mm and 24 mm.

During setup, piston travel should be limited by the rudder hard stops rather than the actuator end stops. Also allow clearance to remove the mounting pin and confirm nothing fouls the hull, quadrant, or nearby gear through the full rudder sweep.

Installation and setup

Pick a location that stays dry in normal operation and keeps the piston rod protected. Avoid direct saltwater exposure and do not mount the unit where it will sit in standing water. Keep the area clear of loose gear, and maintain access to the quick release tab.

Wire the drive so cable runs are as short as practical and well protected against chafe and corrosion. With the motor leads, red to positive extends the ram and black to positive retracts. The unit is pre-filled and sealed; opening the hydraulic circuit introduces air and requires special tools to refill and bleed.

Maintenance and care

Regularly check the security of mounting fasteners and pins, inspect electrical cables and connections for corrosion, and lubricate the mounting pin and rod end with marine grease. Keep the piston rod clean and free from nicks, since rod damage can lead to seal wear and leaks.

For boats that see heavy spray or frequent washdowns, it is worth treating this as an under-deck component that benefits from a drier mounting spot and routine inspection. This style of actuator is a strong fit for cruising and performance boats that want an autopilot ram tied directly to the rudder quadrant without an external hydraulic reservoir or hose run.