Cthon's Crusher - adapted by The QuakeLab from id Software's E1M6 

The QuakeLab - http://www.in2nett.com/stevefu/QuakeLab

        TEXTURES:

        altar1_1 for slab face, metal4_5 for spikes, metal4_4 for remainder
        of slab, met5_2 for blood smear pattern along hallway walls.

        ENTITIES:

        func_train & path_corner

        WHAT TO DO:

        This assumes you want something very similar to E1M6's design. Make
        the slab 160 units high. Make the spikes. You only need to carve two
        different spikes - look carefully at E1M6 to see how they were cut.
        The two center columns of spikes are mirror images of each other and
        are somewhat irregularly spaced, and the two outer columns of spikes
        are mirror images of each other as well. The tops - the sides facing
        the ceiling - of all the spikes are essentially horizontal. There
        should be a total of 20 spikes after all the copying and positioning
        has been done. Select all the brushes that make up this crusher, and
        designate the whole thing a func_train in one shot. Set up the path
        corners - the first should be positioned where the lower right hand
        spike tip (in the picture) is located. This will be the start. The
        second path corner should be very close to the far wall, but along
        the same line as the first path corner.

        OPTIONS:

        Make a trigger or button of your choosing that sets off the crusher.
        Leave the speed as it is (100) or change it to your liking. Set the
        dmg rating to 600 if you want Shamblers to die instantly under the
        crusher - all/most others will be gibbed.