Rigging gear, blocks and pulleys: what the sources say

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. It covers the pulley-type gear that redirects or carries a rigging line. All pages were read on October 9, 2026. The courses that teach rigging are in the guides on chainsaw tickets and certifications by country, and the UK award is on the page for aerial tree rigging. The climbing-side pulley figures are in the guide on connectors and hardware ratings.

Credits. Wording from the SafeWork NSW Tree works code of practice is adapted under the Creative Commons Attribution 4.0 licence, with sentences shortened and reworded. Wording from the WorkSafe New Zealand code is adapted with the source and copyright status acknowledged. TCI Magazine and BSI are described in our own words with links.

Block or pulley: TCI Magazine

A November 1, 2020 article in TCI Magazine, Rigging tools: an overview for ground technicians, separates the two words. The author says a pulley is designed to be used only with the load under it, a positive position, while a rigging block can sit below the load, a negative position, and catch the load while it is being lowered. He describes rigging blocks, often called impact blocks, as double-sheave with rounded soft-edged side plates so a soft sling can hold them, with the rope running through the large sheave carrying the energy with little or no friction, so the energy is spread along the whole rope between the load and the friction device on the ground. He says the bend radius at the moving sheave follows the maker's advice for both block and line, that a ratio of 4 to 1 is usually correct, and that the sling is rated at least equal to the block's working load limit.

SafeWork NSW: pulleys in lowering systems

In the SafeWork NSW Tree works code of practice, a carabiner or shackle is not used in place of a pulley, and rated connection hardware such as shackles is used together with pulleys when assembling lowering systems. It says the lowering rope runs through a diversion pulley when the risk assessment calls for it, to remove the risk of the operator being pulled toward the lowering device and the descending load, and that it runs through pulley blocks when the load needs to be pre-tensioned, in which case natural anchor points are not used. It says hardware is labelled with its age and working load limit and inspected before and after each use, and that damaged hardware is removed and checked by a competent person.

WorkSafe New Zealand: tackle blocks

Section 3.4.6 of the WorkSafe New Zealand arboriculture code says tackle blocks, pulleys and their connecting links, chokers, slings or other means of attachment are inspected before use and removed from service if there are signs of excessive wear or damage. It says strops anchoring pulling blocks are at least 1.5 times the safe working load of the pulling rope, and that a stump used to secure pulling blocks is of sufficient size and stability.

Which standard covers it

BSI's catalogue page for BS EN 12278:2007 describes it as covering safety requirements and test methods for pulleys for use in mountaineering including climbing, and shows it as current and under review. The TCI article, the NSW code and the NZ code do not name a standard for rigging blocks.

Source	Covers	Rating or inspection
BSI, BS EN 12278:2007	Pulleys for climbing	Strength and marking
SafeWork NSW code	Pulleys and blocks in lowering systems	Labelled; inspected before and after use
WorkSafe NZ code	Tackle blocks and pulleys	Inspected before use
TCI Magazine article	Rigging blocks and pulleys	Sling rated at least equal to the block