Cable Weights

[techtech]

Hi All,

 

When estimating the weight of LX bars how much extra to you add for the cables / Multi core?

2 KG per 5 fixtures or something like that?

 

Techtech

[tom_the_LD]

Depends how much cable is up there and of what type.

 

Slightly OT but recently I have been weighing all the stock at a local hire company and cable was one of the things that I had to do. It's surprising how quickly it all adds up!

[Cormac]

I use

every 1.5 mm socapex per Meter @ 0.43kg

every 2.5 mm socapex per Meter @ 0.6kg

 

So I guess trs and date less than a 1.5 socapex

 

Cj

[No Longer A Member 210514]

our 2.5mm TRS is approx 2.1kg per 10metres

[lightsource]

For larger jobs, I add 0.5Kg per fixture as a rough idea, but I've never used truss supplied close to 75% of capacity, so not really an issue for me.

 

2 KG per 5 fixtures or something like that?

 

I would recommend working on a per-fixture basis, rather than grouping them in fives.

 

As others have said, define 5 fixtures...... 5x PAR56 cables would have a very different cable weight to 5x Martin Atomic Strobes.

 

Depending on the size of the job, this could be an issue. It also depends on the lenghth of the cable run, and the span of the truss.

[peternewman]

2 KG per 5 fixtures or something like that?

I would recommend working on a per-fixture basis, rather than grouping them in fives.

With the obvious exception of a PAR bar, but then six is a far more sensible number.

 

I was going to suggest it might be worth BR members compiling some numbers, although I guess TRS and Soca/Lecci pretty much covers most situations, however White Light already do so. Its in there Tech Reference Brochure (PDF), on page T28/page 36 of 64 of the PDF and includes fixture and cable weights.

[Moz]

Hi All,

 

When estimating the weight of LX bars how much extra to you add for the cables / Multi core?

2 KG per 5 fixtures or something like that?

 

Techtech

 

So many variables.. to calculate ! ….This is more of an answer than you bargained for…

 

Cable Weight / lengths = e.g . A 10m and a 5m, (same plugs)

 

Subtract the 5m kg from the 10m kg and you have the weight of 5m Cable only.

 

Divide by 5 = 1m of cable, you can multiply it out from there.

 

Add your headers, and the rest of the equipment, all items weight something.

 

Manufactures specs often vary from the actual weight, when rigged and ready to use.

 

If you think an item weighs nothing (figuratively speaking), hold ten of them on your finger.

 

Allow a nominal weight for each rigging point. Slings & shackles, truss joins, it all ads up.

 

Allow for the weight of the vertical cable drop, of the looms. At trim height.

 

Note:

 

The distance between the end of truss, or cable drop point and the closest hoist pick up point. The truss acts like a leaver increasing the load on the first winch Pick up and decreasing the load on the second Pick up. So the first winch could be the one with the heaviest load.

 

 

So many things to think about…….. will it stay up?

 

Engineers sign off on the capacity of structural rigging points, Riggers will ensure it stays in the air provided they are given the correct load information.

 

Cheers

 

Moz