Brickley Roscowicz Engineering

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October-November 2005

After I built the BRE-100T with a 2-section telescopic boom, I realised a 3-section boom wouldn't be all that difficult. But it got shelved for quite a while as I got distracted with other things. But eventually I got around to building it, and I thought rather than building another crane for it, I would build it as an option for the BRE-550M. And as the 3-section boom proved fairly simple, I decided to add a bit of a challenge by also giving it s Sideways Super-Lift option, or SSL. And here is the result.

As you can see, it attaches to the BRE-550M carrier without any modification, and is raised by the A frame, exactly as the standard lattice boom. Here are some setup shots.

The boom arrives on a low loader, and the crane is made ready, extending the outriggers. The A-frame is used to lift the boom into position. The A-frame is then connected to the main boom lifting linkage. The boom is lifted partially, and the hook cable is run. The SSL assembly is lifted into vertical position and locked in place.

The boom is raised almost vertical in preparation for extending. The inner 2 sections are extended first - they are ganged together with cables so extending one extends the other. Finally the 3rd section is extended, and the crane is ready. Lifting can be done with the SSL either in this position, fully spread as per the photo above.

For this project, I decided to also build a low loader to transport the boom. The prime mover is based on a design I found on the web and I am unfortunately unable to re-locate it to thank the designer. But the trailer is my own design.

The telescopic design was fairly simple, just an extension of the 2-section boom from the BRE-100T. Here is an exploded view.

Using snot plates on the sides proved to be far neater, lighter, and stronger than using bricks as I originally tried. And it also made it easier to attach all the SSL paraphernalia.

Of course getting the SSL paraphernalia to work was not trivial. The Linkage allows movement on 2 axes, to raise and spread the arms. Also the hold-back linkages had to be the right length, be hinged at the right place to allow them to be folded for transport, and also be attached by a linkage allowing movement on 2 axes. Then there had be locking devices to lock the arms vertical, and lock them in the "unspread" position. Spools had to be provided for the allowing easy winding, and a pulley to maintain clearance for the hook cable over the whole mechanism. And with all that, I wanted it to end up looking as authentic as possible, in both the transport position, and the deployed position. I'm fairly happy with the result.

Below are some pics of various parts of the boom detail.

Detail of the SSL mechanism unspread (the bush-pins lock the arms in that position) and...	spread. The parallel linkages stop them from spreading further.	The hold-back linkages and how they are attached to the base of the boom.	From above, showing the pulleys.	From the side, showing the cable spools, and how the arms are locked in the vertical position.

See other pictures here.