Crane lightboxes – anyone done one?

[Peter Normington]

never done one John, but would think they would need to be properly sealed all round, and if memory serves me, the cranes run on 440volt (3 phase)
but 110 feed from a transformer would be the way to go.

I would ask the customer for the relevant power specification, as it would be their responsibility.
but to be honest, this is not the sort of job to undertake, without specialist knowledge, and prior experience.

Peter

[David Rowland]

makes me wonder about a little fan generating some electric up those heights

[Jon Marshall]

We’ve done a lot of them. Some hang under the jib and we weld extra strengthening inside the box. Others fit on the jib and are pretty much standard (good quality) boxes.

[Peter Normington]

quote jonm01:

We’ve done a lot of them. Some hang under the jib and we weld extra strengthening inside the box. Others fit on the jib and are pretty much standard (good quality) boxes.

do you fit them before or after erection?

just wondered how you fit them under the jib…..
and what fixings would you use,

Peter

[Jon Marshall]

They have big ring bolts and hang underneath. They crane erectors put them up when they are putting the crane together.

[Peter Normington]

jon
sorry to sound stupid, but what is a ring bolt?
and how does it attach to the light box?

I probably will never use the info, but I come from a plant/engineering background, and I am just curious. A light box hanging from a tower crane, a couple of hundred feet up sounds a bit dangerous, is it fixed rigidly, or allowed to swing in the wind? and if it is, what measures are taken to prevent the bearing points from wearing?

John was asking advice on fitting them, so these are the sort of questions he needs answering.

Safety would be a major consideration here, and I would think, there would be quite a lot of approvals needed from the crane manufacturers, and the site safety officer, before just attaching anything to a jib (Christmas trees excepted 😉 )

Peter

[Martin Pearson]

Peter, if you have an engineering background then you should know that the lightboxes are usually put up using sky hooks.

I think what Jon refers to as a ring bolt might be what others know as an eye bolt Peter which would mean as you say that the box would be free to swing about a bit under the jib.

[Graeme Harrold]

Again from an engineering background, I would be inclined to let the customer specify where the mounting points are going to be i.e. top or back. Then make the box in such a way that these panels are fully capable of supporting the whole box and let the crane erectors/fitters worry about the actual "nuts and bolts" of fitting. Just specify the minimum number of recommended fixing points and maximum distance between fixing centres. In addition, provide a couple of safety straps/chains.

Last time I saw a sky hook, it was just that, an open jawed hook with no safety gate, designed for quick attachment.

[Martin Pearson]

Graeme, I thought you were an ex-service person?????

If you are then you should know what a sky hook is :lol1: :lol1: :lol1:

[John Harding]

Thanks for the input guys

Jon – You mentioned a good quality box do you have a manufacturer in mind, gonna have a little phone around on Monday see what I can find out

What about the electrics Jon is it three phase 110 240 what have you supplied ?

John

Ps Crane is already up so fitting might be a problem 😕

[Graeme Harrold]

quote martin:

Graeme, I thought you were an ex-service person?????

If you are then you should know what a sky hook is :lol1: :lol1: :lol1:

Not Ex yet, Ive got another 2 years of my sentence to go and no time off for good behavior!!!! 👿

Never fell for the "long wait" or go and get a "bubble" and if asked for a sky hook Id go off and come back with one…………As mentioned before, its a sturdy un-gated hook mainly used for rock climbing ladders as they are normally attached to pre-placed bolts……….Not totally safe, but if you know the limitations of something its safe to be used within them……………

[Jon Marshall]

quote John Harding:

Thanks for the input guys

Jon – You mentioned a good quality box do you have a manufacturer in mind, gonna have a little phone around on Monday see what I can find out

What about the electrics Jon is it three phase 110 240 what have you supplied ?

John

Ps Crane is already up so fitting might be a problem 😕

We normally use SMP but ask for extra strengthening. Also we then get the box strengthened further with internal box tube where the eye bolts go. I think for the electrics we just supply the cable and also steel wire for bracing from the wind.

Oh, and I doubt you can fit it if the crane is already up. We missed a delivery once by an hour or so when the crane was going up and that box never got fitted. Or paid for!