• Trolley Blocks

    Compiled by Ashley McGrew
    Originally Posted 7/25/09

    Using a chain hoist on a standard trolley (not a geared type) means that the load can move easily along the axis of the gantry’s I-beam. This is what makes you able to move a load from one location to another if required. This ease of movement can also be useful because when lifting irregularly shaped objects (like sculpture versus say a refrigeration unit). As tension is applied to the load the trolley can move freely to center itself over the load. This way when you start to actually lift the load it will be coming straight up instead of being partially dragged sideways.

    Once you have the lift started there may be good reasons why you don’t want the trolley to move (gantry can’t be leveled and the material might shift, or the gantry will be moved with the object elevated).

    Under these conditions what you see above is a common sight. A "C-clamp" is keeping the trolley from moving in the direction it is inclined to.

    I am not sure how you feel about having a large piece of metal clamped above a piece of artwork, but I know a few folks who get distracted by the mental image of a heavy piece of steel coming loose and plunging to the detriment of whatever may lie below – be it art or some unfortunate noggin.

    Sometimes you will see something like this. A length of Nylon webbing can make everyone feel a lot more relaxed, and more prepared to focus on other aspects of the task at hand.

    OK and this is?

    What for lack of a more inspired term, I would call “trolley blocks” they are a “homemade” assembly of components from the local hardware store or a catalog outfit like McMaster-Carr.

    The primary components are two I-Beam clamps. They are designed to clamp to the same type of beam that you find being used in most gantries.

    Normally they are used to hang plumbing or wiring combined with other hardware that is connected utilizing threaded rods. In this case they are still clamping to the beam of course, but they are instead acting as “chocks” for the wheels of the trolley.

    It is a virtually no-assembly-required situation.

    The square headed bolts normally used in a more permanent setting are seen here removed and replaced with large wing-head bolts making them quite a bit easier to adjust.

    A wire rope lanyard (buy premade, or crimp one yourself) is inserted through one of the threaded holes in each clamp. Loop the lanyard through the trolley itself and clip the end loops together with a carabineer type spring snap.

    Probably the best feature of the gizmo is that it can live right were it is going to be used. It doesn’t interfere with normal use of the chainfall when not engaged and probably most important of all it is unlikely that someone is going to grab it to use for some other purpose – those C clamps are just way too handy to stay in one place it seems to me.

    I bought my beam clamps at Home Depot but you can get them from McMaster-Carr and probably Grainger.

    From the first catalog source above they add up as follows:

    I-beam clamps
    $ 7.90
    Winghead bolts 90196A720 $4.24 $ 8.48
    24” lanyard 90312A740
    $ 1.85
    2” spring snap 3933T41
    $ 1.09