pulley 13 at the front end of the third ladder section a pulley 14 at the rear end of the fourth ladder section a pulley 15 at the front end of the fourth ladder section a pulley 16 at the rear end of the fifth ladder section and a pulley 17 at the front end of the fifth ladder section the front end of said wire being tied to the working platform 5 in addition for a ladder having six or more ladder sections the wire 7 may be likewise arranged because of the arrangement of the wire 7 described above the extension and contraction of the ladder 4 will not cause the working platform 5 to be raised or lowered this will now be described in more detail with reference to fig2 referring to fig2 illustrating the relation between the first and second ladder sections if the second ladder section is extended through a distance l the pulleys 10 and 11 will be displaced also through the same distance l as a result the distance between the pulleys 10 and 11 is decreased by the same amount l on the other hand the distance between the pulley 11 and the working.