EXE-Rise Taking On The Challenge

Don’t get stuck doing things the old way…

The double-braked ‘Exe-Rise’ chain hoist 1T has a 8:1 safety factor with a single fall of chain, allowing you to lift large loads without requiring a secondary back up.

…Why risk it when we have the solution?img_5978-jpgimg_5979-jpg

Moving Forward With Safety

Would you drive your car without a speedometer?

Why do we lift and move loads without load cells then?

Providing arguably the most advanced load cells on the market with wireless technology why not contact us today and lead the way to a safer industry.

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Now I can see

Ever wanted to get into a better visual position to run those hoist where you can’t quite manage it because of the cable length on the remote? Then we have the perfect solution our 8 and 12 way Wireless hoist controllers! Contact us for more details on our full range of chain hoist control solutions.

Statistically indeterminate loads

In a recent post about D8+ chain hoists, an indeterminate load was mentioned and the need for load cell monitoring and we thought this would be a good point discuss a bit more about what a statistically indeterminate load is and what we can do to protect ourselves against it becoming a problem.

A “statistically indeterminate load” occurs when you have more than two loading points on a truss or three or more loading points on a structure, and this results in an unpredictable load distribution.

The simplest type of lift is a single point lift, for example, one chain hoist lifting a known load, and in this situation you can probably proceed without the need for load monitoring. Similarly, if you are lifting a truss on two chain hoists and again assuming you know the weight of the load your lifting, its evenly distributed and the total load does not exceed the capacity of a single hoist, then again you probably will not need load monitoring.

When you get to lifts involving more than two hoists we enter into the difficult territory known as statically indeterminate loads. Under “IGVW SQ P2” which is the German standard for electric chain hoists that forms part of the VPLT SR2.0 Code of Practice, there is a need to load monitor your hoists when using more than 2 hoist on a single truss.

To try and simplify how you get an indeterminate load, we will use an example of lifting a single line of truss on three chain hoists. Assuming that you’re using fixed speed conventional AC chain hoists of the same type and capacity from a single manufacturer, operating directly from a single controller, then in theory you hoist should run at the same speed when they are evenly loaded. But when those same hoists are unevenly loaded, for example the cables drop from one end of the truss, a group of movers in the middle of the rig, those same hoists can run anything up to 5% differently when unevenly loaded.

As you proceed with a lift, a hoist that is running faster will start to take up more of the load and a hoist that is running slower will be taking less of the load, and there is a chance of hoists becoming dangerously overloaded. In situations like this with an experienced operator who is not being distracted by others or under the pressures of time, it is unlikely to become a serious problem, but in less than ideal situations can quickly become an issue very quickly and just because a truss looks level it’s not always the case its load balanced.

The easiest way to monitor the situation is to introduce load cells into the rig one load cell above or below each hoist will monitor the load the hoist is taking and give a quick visual indication of what the hoist is taking. The load cells do not need to be connected to a complex control system it can be as simple as read outs for the operator to monitor. Although using a “semi-intelligent control” is one of the safest way to proceed as it does not rely on the operator spotting load difference which is harder to do on bigger and more complex rigs where each hoist may be taking different loads. Load cell monitors
come in different types, It’s possible to use a standalone unit that plugs into a hoist controller and many hoist controllers are now able to monitor loads being lifted and stop the procedure if the load shifts outside of a predetermined limit.

Load cells come in a variety of different types with both wired and wireless systems available and most hoist manufacturers have the ability to build them into the hoist. One of the easiest types to use is one that is built into it bow shackle although these are not necessarily the most accurate if the load is not sitting squarely on the centre of the shackle pin.

So to conclude, with the ever increasing complexity of the loads and equipment that is being specified for productions today and the need to meet the required safety regulations, one of the simplest ways to protect ourselves, the performers and the audience and be sure of what we are lifting is to include load cells into the system.

Should you want further information on the load cell systems available and the options open to you please feel free to contact us.

What Is a D8+ Chain Hoist Specification and How Does It Apply to Me?

Within the entertainment industry there are often occasions where it is necessary to move or suspend loads above people. So let’s look at what is involved in selecting an appropriate motorised chain hoist for use in Australia, and how you can provide a safe working environment for the cast and crew who are working the show and a safe venue for the audience who are attending assuming it must be safe to be here… Continue reading “What Is a D8+ Chain Hoist Specification and How Does It Apply to Me?”