What are the types of dock levelers?

There are three main ways to sort dock levelers: by how they are mounted (pit, edge-of-dock or vertical), by what moves the deck (mechanical, hydraulic or air-powered) and by the lip (hinged or telescoping). A pit leveler with a hydraulic drive is the usual choice for a busy warehouse dock. An edge-of-dock leveler suits a dock where the trailers sit close to floor height and no pit can be cut. A vertical leveler fits cold storage and food plants, because the door can close tight to the floor behind it.

What a dock leveler does

A dock leveler is the steel ramp at a loading door that bridges the gap and the height difference between the warehouse floor and a trailer bed, so a forklift or pallet jack can drive straight in. OSHA counts it as a dockboard: its walking-working surfaces definitions say dockboards include bridge plates, dock plates and dock levelers. Every type has the same two working parts: the deck, the main platform, and the lip, the front edge that rests on the trailer. The types differ in where the leveler sits, how the deck is raised and how the lip reaches out. Our dock leveler glossary entry explains the parts.

Types of dock levelers by how they are mounted

• Pit leveler. The deck sits in a concrete pit in the dock floor, flush with the floor when stored. Pit levelers have the longest decks, so they handle the widest spread of trailer heights at a gentle slope. Most new warehouse docks are built with them.
• Edge-of-dock leveler. A short plate bolted to the face of the dock, with no pit. It only covers a few inches above and below the dock, so it works where trailers sit close to floor height. It is the common choice for an older building with no pit, or a low-traffic door.
• Vertical leveler. The deck stores standing up inside the building, and the dock door closes on a flat floor in front of it. That keeps out cold air, dust and pests, which is why food, pharmaceutical and freezer docks use them.
• Portable dock plates and boards. Loose plates that are set in place by hand for an occasional delivery. They need handholds and must be secured so they cannot slide out of place.

Types of dock levelers by what moves the deck

• Mechanical. Springs hold the deck up and an operator pulls a chain to release it, then walks the deck down onto the trailer. There is no motor or pump, but the springs and hold-down need regular adjustment, and the work is done by hand at every truck.
• Hydraulic. A push button runs a pump that raises the deck with a cylinder, and a second cylinder swings the lip out. It is easy on the operator and suits docks that see many trucks a shift. Its faults are pump, fluid and valve faults; our guide to a hydraulic dock leveler that is not working goes through them.
• Air-powered. A push button fills an air bag under the deck from a blower. It is also push-button and has no hydraulic fluid to leak, which some food plants prefer. The air bag and the blower are the parts to watch.

Hinged lip or telescoping lip

Most levelers have a hinged lip that swings out and drops onto the trailer bed. A telescoping lip slides straight out instead, so the operator can set it down a few inches at a time. That helps when the load sits right at the trailer's back edge, such as the last row of pallets or a trailer with a drop frame.

How to choose the right type for your dock

• How many trucks a day. Many trucks a shift points to a hydraulic or air pit leveler. A few a week can be served by an edge-of-dock unit or a mechanical leveler.
• How much trailer heights vary. A dock that sees box trucks and full trailers needs the range of a pit leveler. Trailers that all sit near dock height can use an edge-of-dock leveler.
• Temperature and cleanliness. A cold store or food dock gains the most from a vertical leveler, because the door seals to a flat floor. The dock seal or shelter around the door matters just as much.
• The building. Cutting a pit into an existing slab is concrete work. Where that is not practical, an edge-of-dock or vertical leveler may fit the opening.
• Weight on the deck. Pick the rated capacity for the heaviest loaded forklift that crosses it, not the pallet alone. OSHA's dockboard rule says a dockboard must support the maximum intended load.

Safety rules that apply to every type

The same OSHA dockboard rule applies whatever the leveler. Dockboards first put in service on or after January 17, 2017 must be built to keep a forklift from running off the side edge. The trailer has to be kept from moving while people are on the dockboard, with wheel chocks or another restraint. Portable plates need handholds and must be secured. On a powered leveler, keep the maintenance strut down whenever anyone works under the deck.

Winter at a Denver-area dock

Cold weather shows up first on the moving parts. Hydraulic fluid thickens, so a leveler can rise slowly on a cold morning. Snow and ice packed into the pit or around the hinges can keep a deck from storing flat. Mechanical springs and hold-downs drift out of adjustment as the steel cools and the dock takes hits. Keep the pit clear after a storm, and have the leveler checked before the cold sets in.

Questions about dock leveler types

What are the parts of a dock leveler called?

The deck is the main platform. The lip is the front edge that rests on the trailer. Below the deck are the hinges, the lift (springs, a hydraulic cylinder or an air bag), the maintenance strut and, on many levelers, toe guards along the sides. Dock bumpers on the wall stop the trailer before it hits the leveler; see when to replace dock bumpers.

What are the standard measurements for dock levelers?

The deck width is matched to the door opening, commonly 6 or 7 feet. Deck length sets the slope: a longer deck gives a gentler grade for the same height difference, which is why the busiest docks use longer pit levelers. The door size matters too; see our guide to loading dock door sizes.

Is a mechanical or hydraulic dock leveler better?

Neither is better for every dock. Mechanical levelers have no pump or fluid and cost less up front, but they take more effort at each truck and more spring adjustment. Hydraulic levelers are push-button and suit busy docks, with fluid and seals to look after.

How much does it cost to install a dock leveler?

It depends on the type, the capacity, the deck size and, for a pit leveler, whether a pit has to be cut or rebuilt. A pit cut into an existing slab adds concrete work. Get a quote for your own dock.

How G Brothers helps

G Brothers repairs dock levelers, dock seals and dock bumpers, along with the loading dock doors above them, for warehouses and businesses across Denver, Lakewood and the metro. We work on every brand, dispatch 24/7 when a dock cannot wait and can send a certificate of insurance, usually within 24 hours. See dock leveler, seal and bumper repair and loading dock door repair, or contact us to have your leveler looked at.

Sources

• OSHA, 29 CFR 1910.21: Scope and definitions (walking-working surfaces)
• OSHA, 29 CFR 1910.26: Dockboards