  BACK to N.Y.C. PConsult

## 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 ofa1 = 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) ) andt1 = 4 * sqrt ( L / (10*g) )

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