Explained: Why high-pressure hook loaders are better than lower-pressure alternatives

As the manufacturer of Ampliroll Hydraulic Hooklifts, we at Marrel are ready to clear up a common misconception regarding operating pressures among hook loaders.

Before proceeding, here’s a word of background: As many in the industry know, Ampliroll products run at 4,500-5,000 PSI along with fully compatible piston pumps and actuators.

We didn’t pull this operating pressure out of a hat. It’s long been the standard for hooklifts in Europe. It’s proven itself in America, too. Fleet managers in the U.S. and Canada have relied on high-pressure hook loaders from Ampliroll for decades. They know that in all kinds of weather and every type of job, their performance and reliability come through—load after load, shift after shift.

Now you are being told (by some) that 4,500-5,000 PSI is too high.

To that claim, we respond that high-pressure systems like those used by Ampliroll are your best choice, and for several good reasons:

  • Fact: The higher the hydraulic system pressure (to a certain point), the more efficient it is in transmitting horsepower between two points. Advantage: Ampliroll.
  • Fact: Using a higher pressure reduces the size of actuators needed to achieve certain force requirements. With higher pressures and smaller actuators, heat is reduced. This reduces fuel consumption and permits lower reservoir sizes. Advantage x 2: Ampliroll.
  • Fact: Smaller-size actuators usually equate to less weight. This results in more payload capacity where it counts the most—on the road, day after day in hook loader operations. Advantage: Ampliroll.


The latest reason to specify a high-pressure hook loader

Today’s roll-on/off operators are trending to knuckle-boom cranes that are skid-mounted on flatbed bodies. Hook loaders enable complete removal (i.e., roll-off) of the crane assembly from the prime mover when it’s not required.

Proceed with confidence with a high-pressure system like Ampliroll’s but don’t bother with a low-pressure alternative.

Why? The new knuckle-booms will not work with low-pressure systems! The cranes are all designed to use high-efficiency, high-pressure hydraulic systems like those on Ampliroll.


One parting argument in favor of a system like Ampliroll’s

Some hook loader manufacturers claim that 3,500 PSI systems are “low pressure.” Not true. They are making a distinction without a difference.

Ask any hydraulic system engineer. They’ll tell you that by today’s standards, 1,800-2,500 PSI is in the low-pressure range while 2,500-10,000 PSI is generally considered high pressure.

It’s true that years ago 2,000 PSI was low pressure while 4,000 PSI was high pressure. Nowadays these differences have been blurred. Hydraulic system designers are striving to achieve higher forces and lower weights by increasing pressures.

Your true choice with hooklifts? A high-pressure system of 3,500 PSI—or a more highly efficient high-pressure 4,500 PSI system like Ampliroll.

That’s been our standard since day one. And it’s justifying itself all over again. Go with Ampliroll and you’ll have a system that’s fully compatible with any flatbed-mounted, knuckle-boom crane you may add to your fleet now or down the road!


For selection, savings and service, make Ampliroll your first choice in hydraulic hooklift systems.

Ampliroll Hooklift Systems are manufactured by Marrel – the inventor of the dual-pivot hook loader in 1969 and first again in bringing them to users across the U.S. in 1980. Today, Ampliroll is the only supplier in the U.S.A. of premier hook loader systems and associated equipment.

Unlike many others, we also offer a complete selection of truck-mounted accessories and roll-on/off bodies that we can supply as a package with our hook loaders, allowing for single-source acquisition! Select from aerial lifts, cranes, grapple systems and more. Also choose from cement mixers, dump bodies, flatbeds, septic pumpers, waste containers, water tankers and other interchangeable bodies. In addition, you can select from our line of high-quality pre-owned hooklift vehicles.