Why aisle width decides the fleet before anything else does
Most fleet conversations start with capacity, but capacity rarely eliminates a truck class — weight ratings overlap generously across classes. Aisle width eliminates. A counterbalance truck that cannot turn into an aisle is the wrong truck no matter what its nameplate says, and a buyer who discovers this after the racking is ordered has bought a warehouse that fits no truck it can use. This is why our warehousing solution reads aisle measurements first and truck selection second, and why RFQs to us ask for aisle width before tonnage.
What actually consumes aisle width
- The truck's turning geometry. A counterbalance truck turns its whole body plus load inside the aisle: truck length, wheelbase and steering angle set a minimum aisle that no skill improves.
- The load. Long or wide pallets extend the swept area; a 1,200 mm pallet steers wider than the truck carrying it.
- Clearance rules. Operating practice — and racking protection — wants clearance on both sides of the swept path. Tight is possible; tight with zero margin generates the racking strikes that end up costing more than the aisle ever saved.
- Travel speed and traffic. Shared aisles with pedestrian traffic want more width or more discipline; two-way aisles want both.
The three warehouse equipment families, by aisle appetite
| Equipment | Aisle character | What it buys you |
|---|---|---|
| Counterbalance trucks — EP18 / EP25 / EP30 | Widest requirement: the truck turns its own body in the aisle | Dock work, yard-to-rack runs, no straddle legs to limit pallet types |
| Walkie pallet trucks — ST15 | Narrowest footprint for travel; lifting only to double-stack height | Dock lanes, backrooms, mezzanine feeding at ground level |
| Straddle stackers — ST20 | Narrow aisle racking work without counterbalance geometry | Lift to 3,000 mm on standard forks, up to 5,300 mm max — real racking density in aisles a counterbalance cannot serve |
The stacker row is where warehouse density is actually won. A straddle stacker's legs reach under a standard pallet, so the truck does not need to swing a counterweight mass inside the aisle — it needs only its own width plus clearance. That geometry is why narrow-aisle racking schemes are built around stackers, and why the ST20's 5,300 mm maximum lift is the number that decides how tall the racking can be on a narrow footprint.
Measuring your own aisles honestly
Measure the aisle at its worst point, not its average: the column that sticks out, the fire extinguisher, the parked pallet that is always there. Measure rack face to rack face, then subtract nothing — that figure is what the truck has. Note the doorway and corner transitions too, since a warehouse of generous straight aisles can still bottleneck at a 90-degree turn where the swept path is widest. Sites that measure once and write the numbers into their RFQ get equipment that works on arrival; sites that estimate get the first-week discovery described at the top of this article. When the numbers land between two truck classes, the honest options are: more clearance discipline, a different truck class, or racking changes — and the third conversation is cheaper before the steel is up than after.
Density, cost and the ladder between them
Warehouse equipment choice is really a position on a ladder: counterbalance trucks buy flexibility and pay aisle width; walkies buy narrow travel and pay lift height; stackers buy racking height in narrow aisles and pay pallet-type limits. Most warehouses the size we serve run more than one rung — counterbalance at the dock, walkies at the doors, a stacker in the aisles — which is exactly the dock-to-aisle set our logistics solution specifies. The mix works because each truck runs the aisle its geometry likes, and the fleet as a whole stops paying the aisle tax in every zone at once. Sizing each rung follows the same worksheet as any fleet decision: the capacity guide for the weight side, and this article's measurements for the geometry side.
Aisle width and truck procurement: the timing
The measurements belong in the RFQ, not in the delivery-week discovery. Sites that send rack-face-to-rack-face figures, worst-point notes and corner transitions with their equipment enquiry receive quotations sized to the geometry that actually exists, and the conversation covers the interesting cases — the one aisle that will not take the counterbalance, the corner that eats a meter — while every option is still on the table. After the steel is ordered, those same cases resolve into compromises. The measurement sheet is twenty minutes with a tape and a camera; it is the cheapest consulting a warehouse ever buys, and our engineering team reads it with every fleet quotation because the aisle figures have eliminated more wrong trucks than any capacity number ever has.
Frequently asked questions
How wide does an aisle need to be for a counterbalance forklift?
It depends on the truck's turning geometry and the load, which is why manufacturers publish minimum aisle figures per model. Measure your actual aisle at its worst point and match it against the model's stated requirement before selecting.
Can a straddle stacker work in narrow aisles?
Yes — that is its role. The straddle legs reach under standard pallets so the truck does not swing a counterweight in the aisle, letting it rack at heights up to 5,300 mm on our ST20 in aisles a counterbalance cannot serve.
What is the difference between a walkie and a stacker?
A walkie pallet truck travels and lifts to double-stack height for ground-level work; a stacker adds a mast and straddle legs to lift pallets onto racking. Many sites run both — see our warehousing solution for the split.
Do I measure the aisle or the racking opening?
Measure rack face to rack face at the worst point — including protrusions and the pallet that is always parked there. That figure is the geometry the truck must work within.
Which Granvolt trucks suit narrow-aisle racking?
The ST20 straddle stacker — 2,000 kg capacity with lift to 3,000 mm standard and 5,300 mm maximum — is built for narrow-aisle racking work.