CSCS Mobile Tower key terms

The maximum load a tower or lifting accessory is rated to carry under stated conditions, set by the manufacturer and marked on the equipment. It must never be exceeded during operations.

The load a mobile tower is designed to support in a specific configuration, accounting for height, wind and platform loading. It differs from the SWL because it varies with how the tower is set up.

A manufacturer-supplied table or diagram showing permitted loads at given tower heights, configurations and wind conditions. Operators consult it before placing materials or people on the platform.

The force wind exerts on the tower structure, platform and any sheeting or materials. It increases with height and sail area, and can make a tower unstable or cause it to overturn.

A projecting leg or beam fitted to the base of a mobile tower to widen its footprint and resist overturning. Outriggers must be fully deployed and correctly loaded before the tower is used.

A device that increases the effective base width of a tower, improving resistance to wind and eccentric loads. Stabilisers must be fitted as specified by the manufacturer for the height in use.

A tensioned cable or rope anchored to a fixed point to hold a tower steady against wind or movement. Guys must be installed at the angles and anchor points specified by the manufacturer.

The foot fitted to the bottom of a tower standard that spreads load onto the ground or a sole board. Base plates must sit flat and fully bearing on a firm surface.

A timber or proprietary pad placed under base plates to spread the tower's load over a wider ground area. It reduces ground bearing pressure and helps prevent settlement or sinking.

The load per unit area that a tower transmits through its feet into the ground. It must be checked against the ground's capacity to avoid settlement, sinking or collapse.

An adjustable foot or screw device used to bring a tower upright and level on uneven ground. Correct levelling is essential because an out-of-level tower leans and loads its legs unevenly.

A tool containing a bubble in liquid used to check that a tower is vertical and its platform horizontal. Towers must be levelled in both directions before use.

Describing a structure that is exactly vertical. A tower must be checked as plumb in two directions during erection and before it is put into service.

A vertical tube or leg of a tower that carries load down to the base. Standards are joined by horizontal and diagonal members to form the tower frame.

A horizontal tube fixed between standards at a set height to tie the tower frame together and support the platform. Ledgers must be at the spacing specified by the manufacturer.

A horizontal member spanning across the tower, usually supporting the platform decking and tying opposite standards together. Transoms also help resist racking when braced.

A diagonal member fixed between standards or ledgers to give the tower stiffness and resist sideways movement. Braces must be fitted in the pattern and positions the manufacturer requires.

Sideways distortion of a tower frame caused by horizontal forces such as wind or movement. Correct bracing and ties are the main defences against racking and collapse.

The working deck of a tower where people stand and materials are placed. It must be fully boarded, secured against movement, and fitted with guardrails and toe boards.

A rail fitted along the edge of a platform to stop people falling. Upper and intermediate rails must be at the heights required by the manufacturer and applicable regulations.

A low upstand fixed along the edge of a platform to prevent tools and materials being kicked or blown off. It also helps stop feet slipping off the platform edge.

A system that stops a person who has fallen, usually a harness connected to a lanyard and anchor. It limits injury but does not prevent the fall occurring.

A body-worn arrangement of straps that distributes fall forces across the body. It must be inspected before use and attached to a suitable anchor point.

A fixed, load-rated point to which a lanyard, harness or guy wire is attached. It must be strong enough for the expected load and positioned to limit fall distance.

The process of assembling a tower from its components in the correct sequence. It must follow the manufacturer's instructions and be carried out by trained, competent people.

The controlled process of taking a tower apart in the reverse of the erection sequence. It must be planned and supervised so components are removed safely and stored correctly.

The written guidance supplied with a tower covering assembly, use, inspection and limits. These instructions must be followed and kept available for reference at the site.

Someone with the training, knowledge and experience to carry out a task safely, such as erecting or inspecting a tower. Competence must match the specific work being done.

A visual and functional check carried out before a tower is used, looking for damage, missing parts and correct setup. Any defect found must be reported and the tower kept out of use.

A formal examination of a tower to confirm it is safe and complies with requirements, carried out at set intervals and after events such as high winds. Results are recorded.

A written or digital log of tower inspections, noting date, findings and actions taken. It provides evidence that checks were done and helps track defects over time.

Any damage, wear, missing part or fault that affects a tower's safety or performance. Defects must be reported promptly and the equipment taken out of service until resolved.

A clear label attached to equipment that is unsafe or awaiting repair, warning others not to use it. It is removed only by an authorised person once the fault is fixed.

A record of servicing, repairs and component replacements carried out on a tower or its parts. It helps show the equipment has been kept in safe working condition.

A marked-off area around a tower where people are kept out during erection, dismantling or use. It protects against falling objects and moving components.

Any item that falls from height, such as tools or materials. Preventing dropped objects relies on toe boards, tool lanyards, exclusion zones and good housekeeping.

Keeping the platform and work area tidy, with materials stored securely and waste removed. Good housekeeping reduces trips, dropped objects and fire risk.

A document describing how a task such as tower erection will be done safely, including sequence, controls and responsibilities. Workers must follow it and raise concerns if it is unsuitable.

A careful look at what could cause harm during tower work and what controls are needed. It must be recorded, kept current and shared with everyone affected.

The order in which safety measures are chosen, starting with eliminating the hazard and ending with personal protective equipment. It guides selection of the most effective controls first.

An assessment of the ground conditions, overhead hazards, access and surroundings where a tower will be placed. It informs the choice of base, stabilisers and exclusion zones.

An electrical power cable suspended above the work area. Towers and long components must be kept a safe distance from it, with the zone controlled to prevent contact.

A formal authorisation for a specific high-risk task, setting out conditions and controls before work starts. It records who may work and when, and is closed out when finished.

A pre-arranged set of actions for incidents such as a collapse, fall or fire during tower work. It covers raising the alarm, rescue, first aid and contacting emergency services.

A specific plan for recovering someone injured or suspended after a fall, prepared before work begins. It names the equipment, trained people and steps needed for a safe rescue.

Immediate help given to an injured person before professional medical treatment arrives. Adequate first aid arrangements, including trained staff and supplies, must be in place on site.

The police, fire, ambulance and other official responders called to serious incidents. Site plans should include access routes and contacts so they can reach the scene quickly.

A record of an accident, near miss or dangerous occurrence, completed soon after the event. It supports investigation, legal reporting duties and prevention of recurrence.

An event that could have caused harm but did not, such as a dropped tool landing close to someone. Near misses should be reported so lessons can be learned.

A short, informal briefing on a safety topic given to the work team before or during a job. It reinforces procedures and gives workers a chance to raise concerns.

Documentation showing what training a worker has received and when. It helps demonstrate that people are competent for the tasks they are asked to perform.

Clothing and equipment worn to protect against hazards, such as helmets, gloves and footwear. It is the last line of defence and does not replace other controls.

The legal and moral obligation to take reasonable steps to protect the health and safety of yourself and others affected by your work. It applies to every worker on site.

Work carried out where a person could fall and be injured, including from the tower platform. It must be avoided, prevented or mitigated following the hierarchy of control.

A procedure that physically prevents equipment or power from being operated while work or repairs are carried out. It protects workers from unexpected movement or energisation.