Programmable alarm system for marine loading arms

A programmable marine loading arm alarm system for monitoring the position of each of a plurality of marine loading arms and for providing an alarm when the outboard end of any of said loading arms extends outside the boundaries of a three-dimensional working area, each of said arms including an inboard limb pivotally connected between an outboard limb and a riser, said alarm system comprising:

• a plurality of inboard elevation sensors for sensing a first angle representative of each of the inboard limbs relative to a vertical plane;
• a plurality of inboard direction sensors for sensing a second angle representative of each of the inboard limbs relative to a predetermined horizontal direction;
• a plurality of outboard elevation sensors for sensing a third angle representative of each of the outboard limbs relative to a vertical plane;
• calculator means for using the values of said first, second and third angles to calculate the spatial position of the outboard end of each of said loading arms;
• memory means for storing the working boundaries of the outboard end of each of said arms;
• means for comparing the actual spatial position of each of said arms with the corresponding working boundaries for that arm;
• means for calculating the velocity of any loading arm which extends outside said working boundaries and for using the calculated velocity to determine the position of a second boundary at which said system generates a disable signal;
• and
• alarm means connected to said comparison means for providing an alarm signal whenever the outboard end of any of said loading arms extends outside said working boundaries of said arm.

A programmable marine loading arm alarm system for monitoring the position in space of the end of an articulated arm having an inboard limb pivotally connected between an outboard limb and a riser, said alarm system comprising:

• an inboard elevation sensor for developing a first signal representative of the angle of said inboard limb relative to a vertical plane;
• an inboard direction sensor for developing a second signal representative of the angle of said inboard limb relative to a predetermined horizontal direction;
• an outboard elevation sensor for developing a third signal representative of the angle of said outboard limb relative to a vertical plane;
• means for converting said first, second and third signals into digital form;
• digital calculator means for using the digital values of said first, second and third angles to calculate the spatial position of the outboard end of said loading arm;
• digital memory means for storing the spatial boundaries of a working area for said end of said arm;
• calculator means for comparing the actual spatial position of the end of said arm with said boundaries from said digital memory;
• and
• means for generating an alarm signal when the spatial position of said end of said arm extends outside the working boundaries of said arm.