The Risk Assessment Comes Before the Steel
The single most common reason a guarding project stalls is that somebody has asked for a fence before anybody has completed the machine risk assessment. The assessment determines where the hazards are, which access points need to be interlocked and what performance level the safety circuit has to achieve. Until that exists, any perimeter layout is provisional and any quotation is subject to change. If your machine is new, the builder's assessment and technical file should already cover it. If it is second-hand, relocated or has been modified, treat the assessment as the first line item of the project, not an afterthought once the steel is on site.
Agree Who Supplies What, in Writing
A typical guarding installation involves three parties and the boundaries between them are where projects go wrong. The guarding supplier provides the perimeter structure, panels, posts, doors and door hardware, and installs them to a layout drawing. The machine builder or the site's control engineer provides the interlock switches, safety relay or safety PLC, and the wiring that ties the guard doors into the machine's stop circuit. The site's responsible person completes the risk assessment and the equipment inspection that brings the machine into service. Write those three scopes into the order. The classic failure is a finished fence sitting around a machine for three weeks because nobody was contracted to wire the door switches.
Map Every Reason Somebody Enters the Cell
Before a layout can be drawn, list every reason a person crosses the perimeter and how often: loading blanks, clearing a jam, changing tooling, removing finished parts, planned maintenance, cleaning, and periodic calibration. High-frequency access needs an interlocked door in the right place; low-frequency maintenance access can be a bolted fixed panel removed with a tool. Getting this wrong is expensive in a way that never shows up on the quotation — if the operator has to walk twenty metres round the cell forty times a shift, somebody will eventually defeat the guard, and you will have paid for a fence that has made the site less safe rather than more.
Penetrations, Services and the Things That Cross the Line
Almost every real cell has something crossing the perimeter: an infeed conveyor, an outfeed, cable trays, pneumatic lines, extraction ducting or a chip conveyor. Each one is a decision, not a detail — an opening large enough for product may also be large enough for an arm, which changes the guarding approach at that point. Capture every penetration during the survey with dimensions and heights, and flag whether product moving through it is continuous or intermittent. Sites that skip this end up with an on-site variation and a delay while a bespoke panel is made.
Budgeting and Lead Time
Price a guarding project in four parts: the risk assessment, the guard structure and installation, the safety control system and interlock wiring, and the commissioning and documentation. Buyers who only price the second part are usually surprised by the total. On timing, allow two to four weeks from approved layout to installation for a typical cell, one to two days on site for the structure, and then time for the control engineer and for commissioning. Where the machine is coming into production against a fixed date, work backwards from commissioning rather than from delivery.
What Handover Should Include
Ask for the as-installed layout drawing, a panel and hardware schedule, and written confirmation of the standard the guard structure was designed against. Keep those with the machine file alongside the risk assessment and the interlock validation records, because that is the pack an inspector or auditor will ask for. If the cell layout changes later, a bolted modular perimeter can be reconfigured, but only if you have the original drawing and schedule to work from — which is a good reason not to accept a verbal handover.
Free Survey and Quotation
Rackstor UK Ltd surveys, supplies and installs steel mesh machine guarding across the UK, and will coordinate with your machine builder or control engineer on the interlock scope. Call 0800 654 6955 or use the enquiry form.
Frequently Asked Questions
What should happen before I request a guarding quotation?
Complete or locate the machine risk assessment. It determines the hazard points, which access doors need interlocking and what performance level the safety circuit must reach — all of which affect the layout and the price.
Who supplies the interlock switches?
The guard structure, doors and hardware come from the guarding supplier. Interlock switches and safety control wiring are normally provided by the machine builder or the site's control engineer, because they integrate with the machine's safety control system.
How do I decide where the access doors go?
List every reason someone enters the cell and how often. Frequent access needs an interlocked door close to the task; infrequent maintenance access can be a bolted fixed panel removed with a tool.
How long does a guarding project take?
Typically two to four weeks from approved layout to installation, one to two days on site for the structure, then interlock wiring and commissioning by the control engineer.
What documentation should I get at handover?
An as-installed layout drawing, a panel and hardware schedule, and confirmation of the design standard for the guard structure. Keep these with the machine file and the interlock validation records.