Pictured above: a run of selective pallet racking with wire mesh decking on every level and a forklift working in the aisle beyond, from our project archive (V3-3). The truck in that picture and the aisle it works in were sized together, which is the whole subject of this article.

The truck lease is ending, or a dealer has sent a quote for a newer model, or the business has grown and a second machine is on the list. Nobody in that conversation is thinking about the racking. The racking has been there for years and it works. That is exactly when a new truck gets bought that does not quite suit the aisles it has to drive down, and the first sign is a scraped upright a few weeks later.

A forklift is not separate from the racking. The aisle width, the height of the top beam and the length of the beam were all set around one particular truck. Change the truck and you have changed an input to the design. This is the check we would want done before the order is signed, because at that point changing your mind costs a phone call. After delivery it costs a re-layout.

Start with what the aisle was designed for

On our pallet racking page we publish the aisle ranges we design to: counterbalance forklifts need aisles of 3.5 to 4.0 m, reach trucks 2.4 to 2.8 m, and VNA trucks 1.6 to 1.8 m. They are ranges, not a promise for your unit, because the working figure comes from the actual truck. But they show why the truck type matters more than the make. The difference between a counterbalance aisle and a reach truck aisle, on those published figures, is roughly 1.1 to 1.2 m on every aisle in the building.

That cuts both ways, and both ways cost money:

• Moving to a bigger or longer truck in the same type. The aisle was cut with some working room around the old machine. A heavier counterbalance truck, or a newer model with a longer chassis, eats that room. Operators can still get through, but they are now brushing the uprights, and impact damage on an upright is not cosmetic, as we explain in a bent racking upright: repair, replace or de-rate.
• Moving to a narrower-aisle type. Swapping counterbalance for reach trucks does not make the existing aisles narrower. It leaves you with aisles that are wider than they need to be, and floor you are paying rent on that stores nothing. Capturing it means re-laying the racking, which is a project with a quotation, not a side effect of the new truck.

In both cases the question to ask before signing is the same: what aisle width does this truck need, working with a real load, and does the aisle I have match it?

Do not size the aisle from the brochure

Every manufacturer publishes a turning radius, measured on smooth concrete, unloaded, under ideal conditions. We measure real turning patterns on installed sites and consistently find that the working aisle needs to be 150 to 200 mm wider than the theoretical minimum, to allow for the pallet overhang, the load, and the room an operator needs to work without threading it. A busy multi-shift floor with mixed equipment needs more than a quiet single-shift store.

So when the dealer quotes a turning radius, ask for the turning figure with a pallet on the forks, and ask which model and mast the quote is for. Our own site survey logs the forklift's turning radius for exactly this reason, and we go through the method in forklift turning radius and aisle width.

The truck is also a ceiling

The top beam is only worth having if the truck can put a full pallet on it. Two numbers on the truck's data plate decide that, not anyone's memory of the old truck:

• Maximum lift height, and the load chart. A truck can lift to a stated height, but the load it is allowed to carry at that height can be lower than at the floor. The data sheet's load chart, showing capacity against lift height, is the page that matters, not the headline lift figure. If your heaviest pallet sits on your top level, check the chart for that pallet at that height.
• Collapsed mast height. A mast that reaches the top beam is no use if it will not pass under the lowest duct, sprinkler pipe or roller shutter head on the way to the aisle. We cover how the lowest obstruction sets the whole layout in clear height and racking levels.

If the new truck cannot place a pallet on your top beam, you have lost a level across every bay, which is a much bigger bill than the difference between two truck quotes. If the new truck lifts higher than the old one, that is an opportunity worth pricing: it may allow one more beam level, which we cover in adding a beam level to existing racking. Either way the beam heights follow the truck you own, not the one in a brochure and not the one you might buy.

Forks, pallets and the bay

The forks have to suit the pallets and the beams. Check the fork length and width against the pallet sizes you actually receive, including what your suppliers deliver on, and against the beam length the bay was built to. Non-standard pallets already change the racking, as we describe in non-standard pallet sizes, and a different fork carriage can change the clearance at the load face.

Two special cases are worth knowing about before you commit:

• Double-deep racking needs reach trucks fitted with telescopic forks, because the fork has to reach past the front pallet to the back one. If your fleet is counterbalance, double-deep is a truck purchase as well as a racking one. The reasoning is in drive-in or double-deep racking.
• VNA racking is designed around one truck. The aisle, the setback and the top beam are calculated from that truck's mast width, length and lift envelope, so a VNA fleet change has to be re-verified before the new truck arrives. We wrote that up in VNA truck swap risk.

If the premises will never have a forklift at all, the question changes completely. Walk-behind stackers have support legs that the bay has to be designed around, which we cover in racking without a forklift.

Can the truck even get to the racking?

This is the check people forget because it is not about the racking at all. In a flatted factory the truck has to travel in the goods lift and the floor has to carry it. Both are limits that exist before any racking is installed. We have written about this in racking a flatted factory unit. On any floor, a truck that is heavier than the one it replaces puts more load through the slab, and a narrow-aisle truck needs the floor to be flat to a standard that a normal slab may not meet.

What to put to the dealer, and to us

Before the order is signed, get these in writing from the dealer, from the data sheet and not the sales quote:

1. The exact model, and the mast configuration if more than one is offered.
2. The turning figure or working aisle width with a pallet on the forks.
3. The maximum lift height, and the load chart showing capacity at that height.
4. The collapsed mast height.
5. The fork length and the carriage dimensions.
6. The weight of the truck, and for a flatted unit whether it fits the goods lift.

Then compare that sheet with what you already have: the aisle width as measured on your floor, the height of your top beam, the beam length, the pallet sizes and the heaviest unit load. Where the sheet and the floor agree, buy the truck. Where they do not, the gap is either a re-layout, a different truck, or a conversation to have before the money is spent.

The short version

• The aisle, the top beam and the beam length were all set around a particular truck. Changing the truck changes the design inputs.
• Published aisle ranges: counterbalance 3.5 to 4.0 m, reach trucks 2.4 to 2.8 m, VNA 1.6 to 1.8 m. The working figure comes from the actual truck, with real clearance added.
• Brochure turning radius is a starting point. Real working aisles run 150 to 200 mm wider than the theoretical minimum.
• The load chart at the top beam height and the collapsed mast height decide whether the top level stays usable.
• Double-deep needs reach trucks with telescopic forks. VNA racking is designed around one truck and must be re-verified when it changes.
• Check the goods lift and the floor as well as the racking.

Thinking about a new truck? WhatsApp us on 9107 2601 with the truck's data sheet and your current aisle width and we will tell you whether the two agree before you sign. See the pallet racking page for the systems we build and the aisle ranges we design to.

Related reading: forklift turning radius and aisle width, clear height and racking levels