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more fragmented elevator-system

(e.g. to rescue disabled persons and to evacuate the
critical upper half of the building faster)

  • two-level emergency usage of elevator-basket in case of additional evacuation via the still working part of the elevator-system
    (secured switch for emergency access to basket-level 2)

    possible acceleration- and brake-times ti for an emergency basket-operation :

    For a1 and a2 pointing in opposite directions one gets:
    I )
    v1 = v2 <=> a1 * t1 = -a1 * t2

    II )
    1/2 * a1 * t12 - 1/2 * a2 * t22 = L <=>
    1/2 * (a1 * t12 - a2 * t22) = L <=>
    a1 * t12 - a2 * t22 = 2 * L
    ( L = length of way to descend quickly )


    with possible values of
    a1 = g and a2 = -4*g

    I ) becomes
    g * t1 = 4*g * t2 <=> g * t1 - 4*g * t2 = 0 <=>
    g * ( t1 - 4 * t2 ) = 0 <=>
    t1 = 4 * t2

    t1 in equation II ) :
    a1 * (4*t2)2 - a2 * t22 = 2 * L <=>
    a1 * 16 * t22 - a2 * t22 = 2 * L <=>
    t22 * ( 16*a1 - a2 ) = 2 * L <=>
    t22 * ( 16*g + 4*g ) = 2 * L <=>
    t22 * 20*g = 2 * L <=> t22 = L / (10*g)
    =>
    t2 = sqrt ( L / (10*g) )
    and
    t1 = 4 * sqrt ( L / (10*g) )


    (this page has been updated on September-27-2001)