How to choose a crane skip: capacity, load and discharge

The right skip depends on three things: what you are lifting (concrete, sand, aggregates or scrap), how much your crane or forklift truck can carry, and how you need to discharge. Looking at litres is not enough: a cubic metre of concrete weighs about 2.4 tonnes, so a full 1,000-litre skip comes close to that weight, plus the tare weight of the skip itself. The collection starts at around 100 litres and goes up to 3,000, with load capacities from a few hundred kilograms to over 6 tonnes.

The types

• Conical skips for concrete. Cone-shaped, with a central or side discharge; for pouring at precise points there are versions with a discharge tube, such as the Conical skip with discharge tube Europa Butti.
• Self-tipping skips for cranes. Designed to empty without anyone handling the load; how the discharge is operated is stated on the model's product page, for example the Self-tipping crane skip Officine Polieri.
• Cradle, bicycle and helicopter skips. Shape variants from some manufacturers (Butti, for example), designed for concrete, some with a discharge tube.
• Skips for forklift trucks. Used with a forklift truck instead of a crane, to move loose material around the site.
• Skips for sand and aggregates. For loose material such as sand and gravel: the weight per litre is lower than for concrete, but still over one and a half tonnes per cubic metre.
• Tipping skips and multi-skips. The tipping model (such as the Tekcnoplast one) tilts over to discharge; the multi-skip is a variant of the same type of equipment.

How to choose by job

The features to look at

• Capacity (L). In the collection from 100 to 3,000 litres; for range models, such as "from 250 to 2000 depending on the model", choose the size from the product page. The higher value suits big pours and fewer trips; the lower one if the crane is small or access is tight.
• Load capacity (kg). From about 220 kg to 6,600 kg. This is the maximum weight of the load: it must never be exceeded.
• Tare weight (kg). This is the weight of the empty skip, from a few tens of kilos to over a tonne. It is added to the load when you check the crane.
• Material. Painted steel, high-strength steel or wire mesh. Painted steel should be washed after use to keep it in good condition.
• Levers and latches. These are the parts that wear the most: look at how they are made and how easy they are to reach for cleaning.
• Dimensions. Overall size in mm, to be checked for loading onto the lorry and for access on site.

Common mistakes

• Calculating on litres alone. Concrete and aggregates have very different weights: the weight of the load, plus the tare weight, must be within the crane's capacity.
• Exceeding the rated load capacity. The limit that counts is the one on the plate, not what it "seems to hold".
• Standing under the load. Nobody should be under a raised skip.
• Discharging while the skip is moving. Open the discharge only when the skip is stationary above the pouring or unloading point.
• Not washing it. Hardened concrete reduces capacity and jams levers and latches; after use the skip must be washed and checked.

Frequently asked questions

How much does a skip full of concrete weigh?

About 2.4 tonnes per cubic metre of concrete, plus the weight of the empty skip. Do the calculation before hooking it up.

Can I climb on the skip or stand near it while it discharges?

No. It is lifted and moved with no one under the load, and the discharge is opened only with the skip stationary above the pouring or unloading point.

How do I attach the skip?

At the designated points, with accessories of adequate capacity (chains, hooks, slings).

What is the difference between a self-tipping skip and a conical one?

The shape and the way it discharges are different: the conical skip is designed for pouring concrete, the self-tipping one for emptying without anyone handling the load. The model's product page states the type of discharge.

What do I check before each use?

Levers, latches and hooks. If anything is bent, jammed or worn, the skip must not be used.

You will find all the models in the Self-Tipping Skips collection: to choose the size to suit your crane, ask for a quote or advice from the AMES technicians.