'HORIZONTAL GRAVITY'
Unrestrained, any vessel will drift between 20km and 70km on one tide.
Restrained by the resistance of energy storage flywheels (or generators), 'power' can be extracted.
GUIDES ALSO ACTING AS 'LOCKS' WHEN STATIONARY.
THE CABLE IS NOT ATTACHED TO THE VESSEL.
MULTIPLE CABLES WOULD BE 'FAIL SAFE'..
LOADS AT ANCHOR POINTS CAN BE MINIMISED IF NOT COMPLETELY ELIMINATED WITH THE USE OF HEAVY ANCHOR CHAIN ON THE SEA BED
FOR ESTUARIES AND INSHORE WATERS ONLY
TARGET DRIFT DISTANCE 4km. TARGET DRIFT SPEED 0.5m/s.
FRICTION DRIVE PINIONS (WHEELS) DRIVEN BY STATIC ANCHOR LINE/CABLE PASSING ALONG THE DECK DURING A CONTROLLED DRIFT.
POWER TAKE-OFF FOR MACHINERY, ENERGY STORAGE FLYWHEELS OR GENERATORS.
POWER TAKE OFF AVAILABLE FOR APPROX. 3 HOURS DURING PEAK TIDAL EBB OR FLOW.
(APPROX. 12 HOURS PER DAY.
CONCEPT.
'Horizontal Gravity'? Is it possible?
PROPOSAL.
The idea of 'Horizontal Gravity' may seem impossible but if you imagine a stationary vehicle (car, truck or train) parked on a road with the brakes off, the road then moves at least 12 miles (20km) back and forth beneath the vehicle 4 times a day and is powered by the Moon's gravity, would you call this 'Horizontal Gravity'?
The road, of course, is the surface of the tidal stream which moves predictably back and forth at speeds of between, on average, 0mph and 10mph (5m/s) roughly following a 'Sine Curve'. If you allow your 'vehicle' to be carried with the road (tidal stream), 'energy' will not be generated but if you try to hold, or restrict, the drift speed of the vehicle (or vessel) to half the speed of the tidal stream, tension (or the force in the restraining lines/cables) will need to be resisted. This resistance will come from the wheels of the 'vehicle' driving generators or energy storage flywheels (see sketch). If you now limit the drift of the vessel to a more realistic 4km and reduce the drift speed to 1mph (or 0.5m/s) over a period of 3 hours during maximum tidal ebb or flow (4 times a day) useful 'energy' can be created.
Perhaps a more easily understood explanation of this proposal would be to imagine we were in a cabin on a vessel with the anchored cable passing through the cabin. The cable is static and will pass through our cabin at speeds of up to 6m/s (and more) as the vessel begins to drift. Our task is to slow the drift of the vessel to approximately 0.5m/s during peak tidal flow using an old fashioned 'clothes mangle' in reverse i.e. the rollers (pinions) are driving the handle which in turn is driving generators or energy storage flywheels via a gear box.
The amount of potential energy here will be due to the amount of surface area presented to the tidal stream, the speed of the tidal stream plus the kinetic energy of the drifting vessel.
PROOF OF CONCEPT.
Due to the many variables and unknowns in this proposal such as the mass of the vessel, the length and speed of drift and not least the effect of 'Betz Law' and turbulence caused, small scale trials would be a cost effective method of 'proof of concept'.
METHOD.
A 4km length of anchor line or cable is laid on the sea bed in line with the tidal stream well away from shipping lanes or navigation channels. Heavy anchor chain on the sea bed is connected to both ends of the line/cable to minimise (or eliminate) loads at the anchor points. The line passes through robust guides on the bow and stern of a vessel or semi submerged pontoon. The cable guides would also need to act as 'hand brakes' in order to 'lock off' the vessel in a stationary position until released, or at slack tide (similar to a San Francisco cable car drive system).
Pairs of friction drive pinions (auto or train wheels) designed to 'impinge' on the line or cable are mounted on the deck of the vessel. The pinions are driven by the static cable moving along the deck as the vessel begins to drift with the tide.
The vessel is fitted with 'spoilers' or adjustable drag inducing surfaces in order to increase or decrease 'power'. Additional automatically controlled surfaces which would reduce pitch, roll and yaw in rough sea conditions could be fitted. These would also assist the vessel to follow a predetermined track thereby reducing the load on guides and cables.
The sustained torque (or MW) available at the pinion wheel drive shafts during maximum tidal ebb or flow would prove (or disprove) the concept.
It is anticipated that the very high torque values that could be achieved here together with a relatively slow input rotation speed would suggest a 'smart' gearbox would be required. A CVT (constant velocity transmission) fluid drive is envisaged. The DAF 'Variomatic' drive developed in 1958 by the Dutch motor manufacturer could also be a candidate for development.
SUGGESTIONS.
With the use of MPPT (Maximum Power Point Tracking) for all design parameters, maximum efficiency can be achieved.
Vessels drifting 'beam on' to the tidal flow would maximise power output.
Low profile vessels would be less affected by wind.
The use of Energy Storage Flywheels for this proposal would have advantages.
1. Smooth out turbulent input.
2. Extend output at slack tide.
3. Stabilise output.
4. Power converted from energy storage flywheels by on-board generators only while stationary at slack tide i.e. shore connection attached only when stationary.
CONCLUSION.
This proposal would be relatively inexpensive to develop, less restricted in location, does not require significant depth, easy for access and maintenance, could use existing vessels, less of a hazard to fish and other marine life and most importantly reliable.
Multiple 'HGU's' (Horizontal Gravity Units) operating at peak tidal ebb or flow positioned around our estuaries or inshore waters would give continuous 'clean' power 24/7.
Bob Jones.
Retired Engineer. Surrey, UK. 5th December 2023.
Constructive comments or 'Business Angels' welcome.
Perpetual Motion Moon Power?
