Milk crate tower


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Milk crate tower

Wacky idea #257 of the day

Since they were invented – apparently by an Australian engineer (see below) – milk crates have been used in many other ways besides holding milk containers.

A milk crate chair by Matt Sutter

Everything from furniture to milk crate versions of the Loch Ness monster.

Milk crate Nessie emerges from Australian backyard swimming pool!

Six interlocking milk crates stacked is 186cm high.

They feel stable but they need a flat level base.

They lend themselves to cable ties to tie together and offer numerous points for guying and attaching halyards.

Not sure how strong they would be at a height of 10 or 12 metres and whether they are structurally strong enough to withstand the forces exerted by guy lines etc. Presumably they would have a high degree of wind loading comparable to a steel lattice tower.

Not sure of the actual plastic material they’re made of – PE extrusion? It would be important to find out how strong it is especially where shackles etc might be connected for guying and attaching pulleys for halyards etc.

If six crates are 1.86m high, 18.6m requires about 60 crates (!) so I guess 9m equals 29 crates in a stack! 10m = 32 crates and 12m is about 40 crates.

It would not be practical to assemble a tower crate by crate from the base up as the upper crates would quickly become unwieldy and too heavy to lift. The same problem would arise with sections of a number of crates at a time. So there would be the same problem of the stresses involved in tilting and lifting any horizontal structure into a vertical position especially at the base pivot point. All crates would need to be tied together on all four sides, top and bottom, so requiring (4n + 4) ties where n is number of crates. I assume the interlocking crates would be solid when tied together.

The crates are bulky and may not be so practical for portable deployment. External dimensions are 36cm x 36 cm and 32cm high so 9 would occupy 108 x 108 x 32cm or 0.37 of a cubic metre so 40 crates for a 12m milk crate tower would occupy about 1.66 cubic metres.

One other downside besides wind loading might be the actual weight of the structure should it collapse. Long-term exposure to UV may also be an issue for a more permanent installation.

Below, a table listing various – mostly unrelated – pros and cons – the biggest one, of course, being that using them in this (or any other way besides storing milk containers) amounts to theft in the eyes of the makers and owners of the crates.

proscons
cheap!long/short term “borrow” required
modularbulky
requires no machining or preparation beyond cable tieshigh wind loading
ready-made solid structureweight if tower falls
colourfulUV exposure?

Here’s a Sydney Morning Herald report featuring the Australian engineer, Geoff Milton who designed the milk crate for Dairy Farmers and how they designed it with holes big enough for potatoes to fall through to discourage theft. This doesn’t explain why they made their internal dimensions the perfect size for storing vinyl LPs!

Coincidentally these milk crates were made by Nally, the same name as the manufacturer of Nally Radio Towers that shut down in 2015 when the owner passed away.


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