Skid-base crates

The skid is the crate

On a skid-base crate everything starts with the timbers on the ground. Two or more heavy runners lie along the length. Cross members tie them together, and deck boards lie across the top to form the floor. Walls and a lid are an enclosure built over that base, not the structure that carries the load.

That ordering matters. In a lightly built crate the walls hold the weight and the floor is an afterthought. Here the floor is the engineering and the walls decide only how much protection the cargo gets: slatted, sheathed or something in between.

Lifting, dragging and tying down

Skid timbers are cut with fork entries so a forklift can go in on the end, the side or both. For loads handled by crane the skid takes sling points or lifting eyes bolted through a timber. Skids can also be shaped with an angled leading edge so the crate can be dragged onto a trailer or into a container.

Tie-down lashings and blocking in a container go over or against the skid, not the wall. If your forwarder wants the crate chocked and strapped in a container, say so; we place the strap points where the timbers are, so a lashing never crushes a panel.

Fixing the load to the base

Machine feet are bolted down. Lag bolts pass through the load's own mounting holes into the skid, and where a machine has no feet, a steel frame or timber saddles are cut to cradle it. Then blocking and bracing is added around the load, tied back to the skid to resist braking and shock.

Never trust friction. A load that is only sitting on the deck will slide on a hard stop. For long or tall items we add a strongback along the face that runs across the load, to stop it racking while it is lifted.

• Lag bolts through the machine's feet
• Saddles cut to the load's profile
• Blocking and bracing tied into the skid
• Centre-of-gravity mark on all four faces

Loads that suit it, loads that do not

Presses, gearboxes, compressors, large pumps, engine blocks, fabricated frames and generator sets belong on a skid base. The heavier and denser the cargo, the more the skid earns its place.

A light, bulky object, such as a hollow fabricated shell, gains nothing from a timber base and pays for it in tare. We would move that item to a cleated panel box or a wirebound crate and save the weight.

Tare, cube and export marking

Heavy skid timbers add tare and raise the load's height, because the crate sits on timber that is itself several inches deep. That affects container height planning, so give the destination handling limits. Cube grows by the skid thickness and the wall build on top of it.

The skid is solid lumber and cannot hide behind the plywood exemption. For export it has to be heat-treated and bear the IPPC stamp. NELMA asks for the mark on a minimum of two opposite sides of the finished crate. If you reuse a skid from another crate, replaced boards need their own HT mark, and we settle that at quote.

Skid base versus a standard pallet-type base

A pallet has thin deck boards and short blocks, and it is designed for repeated warehouse handling of moderate unit loads. A crate skid is built from heavier timbers for a single dense item. Using a pallet under a machine invites a collapsed deck and a load on the ground.

Our guide on skids, crates and pallets sets out the comparison. In short, if the item is above what a pallet is made to carry, or it must be lagged down, build the skid.

Common mistakes at the dock

Most damage to skid-base crates happens at the dock, and most of it is avoidable. Drivers lift from the wall instead of the fork entries. Riggers hook a chain around a corner post. A crate with its centre of gravity off-centre is picked up at the geometric middle and lurches. Each of these shows up in photographs after the claim is filed.

Reduce the odds by marking fork entries in bright paint, stencilling the lift points and printing the weight large. Tell the carrier about any off-centre load in advance, and ask for a spotter when a crate is craned. A tipped crate on a skid is rarely a crate problem; it is a handling one.

What the estimator asks

Give the inside dimensions in inches, the gross weight in pounds and the destination country. Tell us where the centre of gravity sits, whether the load is lifted by fork or sling, and whether the crate will be rolled or dragged. A drawing of the machine's footprint with mounting holes saves a round of questions.