Chipper types compared: how regulators sort hand-fed, driven-feed and vertical hopper machines

This page reports what the named codes, regulators and makers say. It is not training and does not teach the work. This page reports what the official source says. It is not legal advice: ask the office named here.

The wider rules for chippers are in the chippers and stump grinders guide, and inspection and record rules are in the machine inspection guide. Courses that teach chipper work are listed in certifications by country.

WorkSafeBC: four feed types

Part 12 of the British Columbia OHS Regulation has a heading for mobile chippers with one section for each feed type. The figures below are the regulation's own.

Section	Type	What the regulation requires
12.68	Hand-fed chipper	A barrier or baffle on the feed side of the rotor to prevent ejection of chipped material
12.69	Self-feeding chipper	A table or apron at least 1.5 m (5 ft) long measured back from the rotor, with sides tall enough that a worker cannot reach the rotating knife
12.70	Driven-feed chipper	A feed table, with any drop-down extension, reaching at least 150 cm (59 in) out from the nip point of the feed rollers, with the nip point at least 210 cm (82 in) from the ground, measured along the table centre line to the lip and then straight down. Side walls high enough that a worker standing on the ground cannot reach the feed rollers. A feed control bar mounted over the top of the guard chute near its feed end; pushing it to its forward limit and pulling it to its rearward limit must each stop or reverse the rollers
12.71	Vertically fed chipper	Hopper sides deep enough to stop the operator reaching the rotor, and in no case less than 90 cm (3 ft) from the top edge of the hopper to the rotor's edge

Section 12.70 also says a driven-feed chipper in use in British Columbia before February 1, 2012 may continue in use if it meets the feed table and side wall rules and has a feed control bar that works in at least one of the two directions.

Australia: the hand-fed machine with in-feed rollers, split by chute height

SafeWork NSW's Woodchipper guide is written for a trailer-mounted hand-fed chipper. It says designs vary but all use a rotating disc or drum fitted with hardened steel blades, and that in-feed rollers come in horizontal or vertical configurations. It says a chipper without an in-feed stop control device, or one whose in-feed tray is under 600 mm high, is operated by two operators so the emergency stop stays in reach, and that where the tray is under 600 mm high, side stop control bars are also considered.

WorkSafe Victoria adapted that guide. Its plant selection section says a machine-fed chipper may suit larger jobs because it controls manual handling risk, and that a smaller portable chipper has a restricted chute without in-feed rollers, which may further prevent access to danger areas. It says that where an employer does not have the most suitable chipper for the job, a more suitable one should be hired or the job sub-contracted. It describes a drop-down table, safety curtain, bump bar, last chance stop and presence-sensing systems as separate safeguards, and says the last chance stop may not be effective alone because it needs the operator to pull a rope. It also covers winches and cranes fitted to chippers, saying winch lines should not use steel wire rope or metal chokers and hooks.

What the three sources do not do

None of the three sources names a chipper size, capacity or a make as better suited to a crew. WorkSafe Victoria's guidance says the risk controls it lists do not all apply to machine-fed chippers, for example bump bars, and that the guidance does not cover all aspects of using a machine to feed a chipper.

Credit: SafeWork NSW text is adapted under Creative Commons Attribution 4.0. WorkSafeBC and WorkSafe Victoria are described in our own words.

Chipper types compared: how regulators sort hand-fed, driven-feed and vertical hopper machines

WorkSafeBC: four feed types

Australia: the hand-fed machine with in-feed rollers, split by chute height

What the three sources do not do

Sources