Handbook

The Counterweight Caddy is a product I developed as part of the ABTT Virtual Ideas Platform project, run by Charles Haines.

Triple E are now developing the Caddy with me for launch in the near future.

The Problem

There are two main issues with the loading system of Counterweight Flying found in many, if not most UK theatres.

They are; the manual handling of the weights, which can be between 10 and 15 Kg each and keeping the loading gallery tidy and safe.

1 Manual Handling

The typical method of loading Counterweights usually involves lifting the weights, which are stacked on the floor, necessitating a lift from foot level. This is followed by moving to a position in front of the cradle to be loaded. In many venues this is achieved by turning or twisting from the stack of weights to the cradle.

Lastly the crew person will load the cradle which may involve leaning out. This will be repeated for as many times as required to balance the load.

For Double purchase systems this needs twice the number of movements per flying set.

Manual handling advice has a dim view of all this as you can see from the illustration below.

A 10Kg weight is at the upper limit of what should be lifted from foot level, so many weights will be above this, and this does not take into the twisting motion and repetition of the process

2 Keeping Things Tidy

Loading Galleries are usually fairly narrow spaces with many weights stacked on the stage side.

These are not always neat, particularly during a fit up, there are limits on how many weights can be stacked, due to the loading of the gallery and also, though unlikely, the chance of knocking a weight off over the kick rail is also a risk.

The loose weights are also a trip hazard when not kept tidy and also other ancillary equipment may need to be stored on the loading gallery.

A Solution

The Counterweight Caddy presents a solution to both problems. I wanted something that at least removed the issue of lifting from below the knee and kept the gallery as tidy as possible. I also wanted the weights to be presented at a counter top height (900mm) and so I went through various models, as discussed below. Manual cranks and electric or hydraulic systems were deemed to complex or too much of a hassle.

Version 1 - Springs The main issue I felt was that quite large springs would be required for a potential weight of 100kg+ (10 weights) and so the Caddy itself would need to be very strong, which adds to the complexity and weight. Also maintenance or replacement of the springs could be quite awkward with minimal adjustment possible.

Version 2 - Springs - 'Dinner Plate dispenser' In this version the springs would be between the upper static top and the lifting plate. Again this is quite complex, adds a lot of load to the frame and would be awkward for servicing, if for instance a spring needs to be replaced, as above. There are also more parts in this version.

Version 3 - Gas Struts Gas struts turned out to be considerably easier to use, adjust, maintain and replace, so this version used those instead

Prototype - Timber Frame & Gas Struts Constructed by Matt Farly and students at Guildhall. Although production versions would be a steel construction, this 'proof of concept' prototype is timber and was displayed at the ABTT Theatre Show 2023. Further guides are added to ensure the weights cannot slip off the lifting plate whilst moving and a single Gas strut can be used, further simplifying construction and maintenance.

Shown below is the wooden prototype built at Guildhall for the ABTT Show