No longer in production, the 18-ton (16, 3 m ton) lifting capacity National Crane 571E boom truck is part of the Series 500E product. This model is equipped with a 27-71 ft. (8.23-21.65 m) three-section boom and comes with an optional 23-41 ft. (7.01-12.50 m) two-section jib (jib model 5FJ41M) for a maximum tip height of 121 ft. (36.9 m).

Self-lubricating “Easy glide” Wear Pads – The self-lubricating pads, standard on the 500E reduce the conditions that cause boom chatter and vibration. The net result is a smoother crane operation. 

Internal Anti-two-block – Standard on the 500E eliminates the external reel and wire. No more snagging reel or wire on obstructions.

Adjustable Swing Speed – A control knob located on the swing motor brake release valve can be easily adjusted to the crane operator’s swing speed preference.

Optional New Integral Steel Torsion Bedbox – Integral welded torsion box and flatbed. Further reduces frame flex.

Auxiliary Stabilizers –

– Independent stabilizer control

– Bolt/Clamp-on rear stabilizers

Quick-reeve Boom Tip and Sheave Blocks – These standard features simplify rigging changes.

 Pre-painted Components – Painting crane components before assembly reduces the possibility of rust, improves serviceability, and enhances the appearance of the machine.

Burst-of-Speed Winch – Provides faster winch payout and pickup of unloaded cable.

Improved Serviceability –

– A removable winch allows the internal telescoping cylinder to be removed quickly, without dismantling the boom.

– Bearings on the boom extend and retract cables can be greased through access holes in the boom side plates. – Internal anti-two-block wire routing eliminates damage potential.

– The boom sheave case is open, allowing access to replace the internal anti-two-block wire and to observe internal boom components.

– Pre-paint reduces rust.

– Internal boom parts have been reduced, decreasing service time when rebuilding the machine.

State-of-the-art Hydraulic System

– Provides the smoothest operation in the market.

– The hydraulic system features a control strategy of constant pressure, and flow on demand to optimize performance. This control strategy matches the required flow to the demand (speed) of the function while the variable displacement piston pump is regulated to maintain constant pressure to the eight section main valve. Because the pump pressure is constant, the multi-function operation is precise, and smooth metering is assured regardless of load.

– Main valve spools are designed to both meter the flow and limit the maximum flow to each function. Available oil flow is optimized by using “gravity” for Boom down – no pump flow is necessary.