Dock lifts are a type of scissors lift with a large platform. They are used primarily to load/unload materials from trucks to a dock or to the ground.
A dock lift provides a number of benefits.
✓ They are the best solution for loading and unloading trucks for a ground level application.
✓ They eliminate the danger and space requirements associated with a ramp and they improve safety by eliminating manual handling of freight from the truck bed height to the ground.
✓ They can be found in different sizes and lifting capacities to suit a wide range of loading dock applications (and yes, they can be custom made).
✓ There is more secure level unloading from the bed of a truck than any other alternative.
✓ Dock lifts are the only equipment able to reach from ground level to any range of truck size, from low step vans to large refrigerated reefers.
✓ They allow your lifting equipment (forklift, pallet jack, walkie, etc.) to load or unload most trucks you will receive.
✓ A dock lift replaces concrete ramps and truck wells.
CHOOSING A DOCK LIFT
STEP 1: Choose What Application Works Best for You
Top of Ground Style
Pit Mounted Recessed Lift
Top of Ground Dock Lifts:
✓ They can be launched on any flat concrete slabs.
✓ There is no need for pit work.
✓ You can move the dock lift in the future without difficulties.
✓ Their capacities range from 4,000 lbs. up to 15,000 lbs. and the size of the platform from 6” to 6’ up to 8’ X 12’.
✓ The price of a ground dock lift is usually higher than the cost of the recessed units. Although if you sum the cost of the pit construction, the price of the top of ground dock lifts can be quite competitive.
Benefits of The Pit Mounted Recessed Dock Lifts:
✓ These units are usually less expensive than the Top of Ground units.
✓ The main benefit is that these units are mounted flush with surrounding surfaces, so they will not become an obstacle to drive over traffic (this is important to keep in mind mainly if the dock lift will be installed in a doorway).
✓ Recessed units offer level loading at ground level and at truck height. When mounted within the face of docks, they can provide easy dock to ground access (top of ground units can do the same if the units are mounted immediately adjacent to the dock and the approach ramps are shortened.
STEP 2: Platform Size
The platform size is determined by the type of transport equipment that will be used to load and/or unload trucks. 99% of all applications are mentioned below:
- The minimum suggested platform width is 6’.
- Guardrails use 4’ - 8’ of usable platform width on some models. Keep in mind there should be at least 4’ of clearance on each side of the widest load as well as a 48’ wide pallet for ease of maneuvering.
- When the loads are wider and/or some users like to unload two pallets side by side, the 7’ and 8’ wide platforms are the best options.
- When the loads are four wheeled carts or baskets, or the load is limited to two-wheeled hand carts, then a 6’ platform length is more than enough.
- An 8’ platform length is considered as minimum for the manual pallet jacks.
- Power pallet jacks works better with 10’ lengths to fit the load in a comfortable way
- Straddle stackers work well on 10’ platforms.
- Fork trucks are usually much longer, so they normally require platforms in the 10’ to 12’ range.
- Unusual loads may require custom designed units with platform widths of 10’ - 12’ and platform lengths of up to 65’.
STEP 3: Capacities
✓ Lifting Capacity:
When the size of the platform has been determined, you just need to add the maximum weight of the goods being loaded/unleaded + the weight of the transport equipment + the operator’s weight to arrive at a lifting capacity.
✓ Axle Rating Capacity:
Axle loads on manually propelled carts and pallet jacks are too light to be of concern.
Manual pallet jacks divide payload weight between two axles
Powered pallet jacks and straddle stackers usually concentrate 60% of the combined payload and equipment weight on their rear axle. Powered pallet jacks can move heavier loads than manual equipment. Fork trucks usually concentrate 80% of the maximum payload plus fork truck weight on the front axle, very few trucks may run up to 90% concentrations.
It is wise to compare the axle loads produced by your equipment vs. the rating of the dock lifts to be safe.
✓ Roll over capacity:
This capacity only applies for recessed units, and it refers to the maximum axle load allowed for vehicles driving over a fully lowered lift. The majority of recessed dock lifts are rated for 10,000# axle load slow speed drive over. It is important to keep in mind that large specialty vehicles and high capacity fork trucks with small hard wheels can exceed these limits. In those cases, it is important to warn the lift manufacturer and they can modify the lifts to accommodate larger loads with thicker deck plates and other forms of reinforcement.
STEP 4: Power Units and Controls
The operator who rides the lift must be the one controlling the up down controls, if operated in a different way, could cause an accident. NEMA 4 push-buttons, usually mounted on cords, are the standard controls for most companies.
These are some of the items that can be adapted/replaced from the power units and controls:
✓ Cords length can be adapted (these could be longer for security options).
✓ The hand held controls can be replaced with key lock push-buttons that are mounted on the platforms.
✓ Limit switches may be added to cause the lift to stop at fixed dock heights.
✓ Power units on top of ground units are usually mounted on the lifts and covered with weather protection.
✓ Recessed lifts typically have remote power units that are mounted inside buildings, but weather covers can be ordered for outdoor mounting.
✓ Oil immersion heaters are important options for power units that will be exposed to cold winter outdoor temperatures.
STEP 5: The Size of the Bridges
The size of the bridge is dictated by the gap from the lift to the back of the truck bed. Ideally, there should be a 4” to 6” extension onto the truck bed.
- When lifts are located inside of buildings with a wall between the lift and the truck, the bridge (longer than usual) can rest against a wear strip on the wall and will then automatically reach into the truck as the lift is elevated and retract as the lift is lowered (in these cases, extra weight is not a concern).
- Bridge weight is dependent on both length and capacity. Manually operated bridge weight is a concern when the bridge is 24” or longer.
- There are options to mitigate bridge weight such as splitting the bridges into two sections, aluminum bridges or hydraulically operated bridges with push button controls.
Other things to keep in mind is that there are other additional options such as special paint finishes, special platform surfaces, wheel chocks, hydraulic fluids, gates, among others.
If you need more information on choosing the right dock lifts (or loading dock equipment in general) for your premises, please contact us, it will be our pleasure to serve you.
Service areas: Northern New Jersey (Bergen, Passaic, Hudson, Union, Essex, Morris, Hudson, Hunterdon, Middlesex, Mercer and Somerset county/counties), Manhattan, New York City, Brooklyn, Queens, Staten Island, Bronx, Westchester, and Rockland.