Monkey Tower

[kitlane]

Ignoring the dynamic load and friction, this could be reduced by using a multiple-block arrangement (e.g. a Gun Tackle using two pulleys reduces the force on the rigging point to 100% of the load). You have to pull the rope twice the distance but the force applied is halved.

I don't see any way of reducng the load to 100% of the weight of the kit. You yourself have already mentioned 50% of force to lift. Even using 10 blocks only reduces it to 110%, friction cannot be ignored and as more block are added the friction is increased along with the additional weight of the lifting tackle. Equally the snatch force has to be considered.

 

 

 

Yes. My bad!. I meant to type 150%. Slip of the keyboard. And I was unclear when I stated '..but the force applied is halved.' That, of course, is the force applied by the person pulling the line, not the force applied to the rigging point. Basically, my comment was somewhat less than helpful.

[knightdan65]

Your students are there to learn. It will be much better to teach them how to use widely used equipment, such as a scaff tower, competently and safely as part of their education. Your students are much more likely to be asked to use a scaff tower in later real life, particularly if not working within a standard theatre environment. Erecting and dismantling a scaff tower is also a good practical lesson in teamwork that cannot be taught in a classroom or over a video link.

 

This is also a great point I think.

I wonder - as a total aside - what the process would be to get the OP registered as a PASMA trainer / assessor. Wouldn't it be great if students could be taught the correct 'PASMA' process for erecting the tower, and leave college with an industry ticket too?

 

In the past we've sent small groups of students who were keen to get PASMA trained but budget constraints have stopped us doing so. What you suggest is intriguing and I think I might propose it, though the college would stipulate that I continue to supervise regardless (and rightly so), so I doubt they'd stump up the dosh if the only reason for doing so is to give students a better experience. Sadly, this seems to be the precedent in FE these days.

 

 

 

 

Lots of food for thought here folks, thanks very much. On reflection, I think enough people have voiced similar concerns about the nature of the Monkey Tower to persuade me against it. Genies etc are unsuitable due to their weight and Tallescopes only enable a single operative. So it looks like I'm back to scaff towers as many have advised. I've contacted Interlink to design a custom tower with staircases instead of ladders and oversized trapdoors, which should make getting equipment from the floor to the bars a bit easier. So in principle we'd use that for rigging and keep our existing span 500 for accessing tighter spaces.

[dje]

In the past we've sent small groups of students who were keen to get PASMA trained but budget constraints have stopped us doing so. What you suggest is intriguing and I think I might propose it, though the college would stipulate that I continue to supervise regardless (and rightly so), so I doubt they'd stump up the dosh if the only reason for doing so is to give students a better experience. Sadly, this seems to be the precedent in FE these days.

 

Yes, granted, it would add great value for the students however add little value to the college.

 

Lots of food for thought here folks, thanks very much. On reflection, I think enough people have voiced similar concerns about the nature of the Monkey Tower to persuade me against it. Genies etc are unsuitable due to their weight and Tallescopes only enable a single operative. So it looks like I'm back to scaff towers as many have advised. I've contacted Interlink to design a custom tower with staircases instead of ladders and oversized trapdoors, which should make getting equipment from the floor to the bars a bit easier. So in principle we'd use that for rigging and keep our existing span 500 for accessing tighter spaces.

 

I'm going to be curious at the cost of custom designed tower. Sounds expensive! Also with stair stringers, you're definitely going to need a wide thing.

 

Personally I would suggest whether it might be possible to get somebody to produce some sort of davit for your existing tower... ie so equipment can be hoisted up outside the tower, and then manoeuvred into the platform. Rather than being transported up the inside. Yes, as standard, they'll tend to prohibit weight being added outside the footprint of the tower. However that might be open to engineering on account of (a) 2 people in the basket each weighing 60+kg counterbalancing a fixture of max weight 30kg; and (b) the outriggers being deployed in the lift area. The SWL of your Span 500 is surprisingly high, so I wouldn't be at all surprised to find something along these lines being possible.

[kerry davies]

Stair towers already exist and are not necessarily prohibitively expensive. There is also the possibility that a second tower with a bridge between the two provides the necessarily large working platform which also reduces the need to move it. Tallies cost up to £4K plus and the Monkey Tower is not cheap. For that sort of money you could cover the entire space in tower scaff so there is leeway.

 

Did you guys know you can hire or buy individual treads to create your own staircases?

 

If the original tower was purchased locally then a mooch around their warehouse is always worth it. I found some odd bits of kit in back of my old supplier that became a set I was praised for in The Stage. I didn't tell them it virtually designed itself, they thought it was "inspired".

[the kid]

In the past we've sent small groups of students who were keen to get PASMA trained but budget constraints have stopped us doing so. What you suggest is intriguing and I think I might propose it, though the college would stipulate that I continue to supervise regardless (and rightly so), so I doubt they'd stump up the dosh if the only reason for doing so is to give students a better experience. Sadly, this seems to be the precedent in FE these days.

 

Yes, granted, it would add great value for the students however add little value to the college.

 

 

Don't be so sure.

 

Having a trained staff member means:

Training other staff members (see estates etc).

Being able to offer external training as wanted.

 

 

I am intrigued about the load on the bars, as I am fairly confident about them are some pretty mighty IWB's, but thats another time. In all it comes back to spending a bunch of money on something that is needed. When far more is needed to be spent than "acceptable".

[sunray]

Ignoring the dynamic load and friction, this could be reduced by using a multiple-block arrangement (e.g. a Gun Tackle using two pulleys reduces the force on the rigging point to 100% of the load). You have to pull the rope twice the distance but the force applied is halved.

I don't see any way of reducng the load to 100% of the weight of the kit. You yourself have already mentioned 50% of force to lift. Even using 10 blocks only reduces it to 110%, friction cannot be ignored and as more block are added the friction is increased along with the additional weight of the lifting tackle. Equally the snatch force has to be considered.

 

 

 

Yes. My bad!. I meant to type 150%. Slip of the keyboard. And I was unclear when I stated '..but the force applied is halved.' That, of course, is the force applied by the person pulling the line, not the force applied to the rigging point. Basically, my comment was somewhat less than helpful.

No worries, it happens to us all.

[knightdan65]

Update (for those interested in how this thread panned out):

 

Interlink have designed us a custom tower with an appropriate work height and a built in 3-1 pulley system to lift fixtures up through an oversized hatch. We'll retain our single width for focusing / tight spaces. Thanks all for your input

[sandall]

Sounds a good result. I did something similar a while back when needing a tower for an awkward space.

[the kid]

Would be interesting to see the new thing in use.