The long-reach boom is the extended configuration of the excavator boom for work at great reach or digging depth. A 22-t excavator's standard boom is around 6 m boom + 3 m stick — the long-reach boom extends this to 8-12 m total reach. Applications: waterway maintenance, embankment care, high-reach demolition and deep excavation in special foundation engineering.
Configurations: standard long-reach boom with extended boom (8-10 m), Super-Long-Front (SLF) with boom + stick combination up to 22 m reach (Cat SLF series, Liebherr Litronic UMF, Komatsu SLF series), high-reach demolition (UHD Ultra-High-Demolition) with 20-30 m working height for large-scale demolition (see demolition excavator), material-handler booms for ports and recycling (see material handler).
Design consequences: the long-reach boom reduces digging and lifting force because the counterweight of the base machine must act further from the pivot with the arm extended. Practical consequence: a Cat 320 with standard boom lifts 2.2 t at maximum radius; with 12-m long-reach only 0.4 t. This drastically reduces the application range — the long-reach excavator is a specialty machine for reach, not for large-scale excavation. The base machine often needs reinforcement (extended counterweight, reinforced undercarriage).
Application focus: waterway maintenance on canals, rivers and streams (bank vegetation cutback, sediment removal, embankment care), dam and dike rehabilitation (reach into lower areas), wet excavation with limited excavator access, embankment care on rail lines (excavator on rail embankment, reach over the slope), large pit clearance (excavation from deep pits without excavator repositioning), façade cleaning and maintenance on large structures (church-tower restoration).
Prices and rental: conversion of a standard 22-t excavator to 12-m long-reach: EUR 25,000-45,000 conversion cost. Alternative: purchase of a dedicated long-reach excavator (Cat 320D UHD, Liebherr R 926 SLF, Komatsu PC290-11 Long Front). New prices for 22-t long-reach excavator: EUR 190,000-260,000 (with standard boom kit for baseline use). Weekly rental at specialised rental companies (Kiesel Baumaschinen, Bauunternehmen Reichenberg, Nagel-Group): EUR 3,500-5,500 excluding operator. After the long-reach assignment, the excavator is often reconverted to standard boom for flexible ongoing use.