SPERRY MARINE 03956 884272 RUDDER ORDER COMPUTER

The Sperry Marine 03956 884272 is a critical electronic component, specifically a Rudder Order Computer (or Steering Control Interface board) used in Sperry Marine steering systems.

Given your location in Bhavnagar, you are likely dealing with this part in the context of the Alang ship-breaking industry or marine automation salvage. This board is a “bridge” between the navigator’s input and the hydraulic steering gear.

Technical Function & Role

In a Sperry steering system (such as the NAVIGUIDE or NAVIPILOT series), this board performs the following tasks:

• Order Comparison: It receives the “Rudder Order” signal from the bridge (Handwheel or Autopilot) and compares it against the “Actual Rudder Angle” feedback from the rudder stock.

• Error Calculation: It calculates the difference between the ordered position and the current position.

• Solenoid Control: It sends the electrical command to the hydraulic steering pumps (usually via the Steering Control Unit or SCU) to move the rudder until the error is zero.

• Limit Monitoring: It manages electronic limit switches to ensure the rudder does not exceed its maximum mechanical travel (typically 35° or 45°).

Technical Specifications

• Part Number: 884272

• Cage Code: 03956 (Identifying it as a Northrop Grumman / Sperry Marine manufactured part).

• System Context: Often found inside the Steering Control Unit (SCU) or the main steering rack.

• Connection: Interfaces with the Follow-Up (FU) and Non-Follow-Up (NFU) control circuits.

Common Failure Symptoms

If this board is failing, you will typically see one of the following issues:

1. “Rudder Fail” Alarm: The system detects a mismatch between the order and the response.

2. Rudder Hunting: The rudder oscillates back and forth rapidly without finding a steady position (often caused by failing capacitors or a faulty feedback potentiometer on the board).

3. Dead Spot: The rudder moves in one direction but not the other, usually indicating a failed output relay or transistor on the 884272 board.

Maintenance Note for Alang/Bhavnagar Techs

• Potentiometer Calibration: If you replace this board with a used one from a ship-breaking yard, you must re-calibrate the “Midships” and “Hard-Over” settings using the trim-pots on the board to match the specific vessel’s rudder feedback.

• Visual Check: Inspect the board for “pitting” or corrosion from salt air, as these are often located in steering gear rooms which are not always climate-controlled.