Method for constant tension and slippage setting on a reel using accelerometers to detect rotational direction

A method of using at least two accelerometers in automatically determining a direction of rotation of a spool, said spool having a horizontal spool axis, a first spool end and a second spool end, on a reel as a component of automatically maintaining a relatively constant tension and a relatively constant slippage load on an umbilical which is deployed from said spool on said reel by being clamped to a subsea drilling riser where said relatively constant tension is determined by a motor torque on a motor and said relatively constant slippage load is determined by a frictional load on one or more slip clutches, comprising:

• determining an initial radius to said umbilical on said spool, a diameter of said umbilical, a distance between a first side flange and a second side flange of said spool, and a distance of said umbilical from said first side flange of said spool;
• counting the rotations of said spool;
• and
• determining said direction of rotation of said spool by fixing the position of said at least two accelerometers in or on said first spool end or second spool end at an angle other than 0 degrees, 90 degrees, 180 degrees, or 270 degrees in relation to said horizontal spool axis such that when a first accelerometer is rotating past 0 degrees, the acceleration reading of a second accelerometer will be increasing or decreasing as an indication of whether said spool is rotating in a payout direction or a take-up direction.