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Homework Help: Can someone help me to design a boat inclined lift ?

  1. Dec 13, 2012 #1
    I'm clueless how to start!. Here is the description:

    A canal operating company is proposing to build an inclined plane to lift boats between
    two points with a vertical height difference of 55m. Currently the boats have to travel a
    distance of 6km through 19 canal locks to achieve the same vertical height.
    An example of a successful inclined plane at St Louis/Arzviller, in North East France, will
    be used as the model for the design. Details of this inclined plane are given in the
    following web sites:
    The company proposes to lift a moving canal lock which has the same dimensions as the
    existing static locks on the canal. The lock is supported on 32 wheels across 4 axles
    which run on rails. The moving canal lock will be counterbalanced by two
    counterweights attached to the moving canal lock by two groups of 14 cables winding
    onto two winch drums at the top of the structure. The winch drums are powered by two
    electric motors which power the start of the lift and control the speed of the lock or
    counterweight in its descent.
    Initial design work has been completed which proposes that:
    When descending the incline the moving canal lock is 25T heavier than the total mass of
    the counterweights and when ascending the incline the moving canal lock is 25T lighter
    than the total mass of the counterweights.
    The moving lock is sealed at either end by a solid steel plate forced onto neoprene seals
    by hydraulic rams exerting 5T pressure

    As an independent consultancy you have been employed to:
    (i) check the calculation work of the canal company. You must present to the
    canal company a set of calculations to confirm :
    (a) The linear length of the canal track associated with the proposed angle of the
    (b) The velocity of the moving canal lock
    (c) The water saving achieved per lift compared to original series of locks
    (d) The cost of each lift

    Vertical displacement 55m
    Moving canal lock size 40.0m long, 6m wide, 3.5 m height allowing 0.5m of height above
    the water level
    Mass of empty lock 300T
    Density of water 1kg / m3
    Angle of incline 24.25
    Electric motor power 90kW each (operating at 70% efficiency)
    Transit time ascent and descent ) 4 minutes
    Average displacement of loaded pleasure boat 20T
    Average displacement of commercial barge fully laden, 400T including 300T of load
    Pleasure boat average fuel consumption 0.2 litres /km
    Laden commercial barge, average fuel consumption 10 litres /km
    Fuel oil = dodecane C12 H26 , Density = 0.755g/cm3
    , long term BOD high
    Cost of diesel fuel to power barges and pleasure craft=£1.50 per litre
    Cost to users of using incline plane =£0.1 per ton of loaded boat for each lift.
    Cost to canal company of replacement water = £0.10 per m3
    Cost of electricity £0.20 per unit (1 unit =1 kWh)
    A duplicate moving lock (kept as a spare) is located 25m away from the incline plane at
    the same level as the bottom canal
    Estimated capital cost of build £1.5 million
  2. jcsd
  3. Dec 13, 2012 #2


    User Avatar
    2017 Award

    Staff: Mentor

    A sketch is usually a good way to start.
    The length of the incline can be calculated with geometry. This, together with the required time, gives you the velocity as well.
    For c, consider how much water is required for every cycle of a lock.
    d is more work, I think you are supposed to calculate the electricity costs.
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