An often-overlooked element of a silage clamp is the handrail that runs (or should run) around the top of the walls. In so many cases the rails are damaged, missing or just not capable of doing the job of keeping everyone safe. Many are the clamps where the rails show the scars of those unintentional handrail / buckrake interfaces and it’s quite clear that there will only ever be one winner in that meeting. So why don’t we make a more robust barrier that will take some proper punishment from the buckrake man?

It would be technically possible to design a crash barrier type of structure that’s fixed to the top of the wall that would be able to resist vehicle impacts. Possible but not practicable – the costs would be astronomical. It all comes down to regulations and leverage. The regulations give designers the information to design a safe clamp and it is now law that a silo is designed to these requirements. In order to try and make a clamp “affordable” the regulations assume the compaction vehicle will not hit the wall. If we were to design a wall that included a vehicle impact load, the increase in wall, foundations and costs would be enormous. Making a safety rail that would take impact loads would make this issue even worse as the leverage from the point of impact down to the foundation would be a metre more than the top of the wall. So, if you can’t rely on the rail to stop the tractor falling off the clamp…….

What is a silage clamp safety rail for?

It’s a complicated matter but the safety rail should more accurately be named the “safety-sighting rail”, It’s a subtle but important difference and key to understanding what this rail is actually designed to do. The rail is there for two roles. Firstly to aid the buckrake driver to judge where the wall is – that’s the sighting part of the term. And secondly the safety part is to prevent people from falling off the clamp during the sheeting and uncovering of the silage.

The first part - sighting - is easy to deal with, you need a structure that’s visible and clearly marks the line of the wall. The second element - safety - is more difficult to determine and we need to consider the legislation that covers this area. There are two areas of edge protection or fall arrest legislation. One covers structures during the construction phase and relates to working at height in the Health and Safety at Work regulations. This requires a robust structure with a handrail at least 1100mm above the “platform” level and a gap not greater than 470mm between rails. You also require a “toe” board of 100mm height to prevent a foot slipping through the gap or items rolling off the raised level. The other regulation relates to building control and have even stricter requirements. 

The trouble is, neither of these regulations really cover the use of a silage clamp. A building site may have many different trades people working off a scaffolding, every day of the week, for months. There are also likely to be workmates or the public at risk below them. The legislation really considers this as a temporary condition for a limited period. Clearly a silage clamp is a different environment as work only occurs for a very limited duration and in the past HSE inspectors have treated clamp safety rails with a degree of some individual interpretation. There are more lax requirements for areas that require access less than once a month but it’s unlikely your silage clamp qualifies for this, at least during the winter months.

So do I need to worry about the rails on my clamp?

You do because falls can be fatal and even if the HSE didn’t pick up on your old silo rails in the past, there is a very good chance they will in the future. This is because the approach to safety is changing and so too is the funding of the HSE; this has changed fundamentally. Previously the HSE was funded by the government and any funds, fines or prosecutions went into central governments treasury. This has now been replaced by Fee For Intervention or FFI.  Now government funding of the HSE has been drastically cut and in its place the HSE now gets to keep (some) of the revenue from FFI. The HSE now needs to generate the majority of its funding from these FFI fines. Those of you who are partial to the odd conspiracy theory may be left thinking the HSE will be issuing fines left right and centre then sitting back to count the cash. The most recent figures on prosecutions don’t seem to back this up but please be aware, the HSE are looking at a massive shortfall in its funding. So don’t be surprised if you face a fine for a breach of the law that might have previously been overlooked.

So what can you do to make your clamps safe?

First and foremost you must carry out a risk assessment, or at least review and update the existing ones. The actions might require replacement, upgrading or fitting of safety rails that will meet the working at height regulations. This means the top of the upper rail should be 1100mm above the top of the wall, and there should be an intermediate rail about halfway up.

Do you need a toe board?

Probably not, the silage will settle below the top of the wall and a 100mm lip should be created. If the silage is heaped up above the top of the wall, then a toe board might be required unless you have a good gully at the top of the wall.

There are a number of suitable materials to form the rails but thick walled steel tube such as scaffolding tube, is probably the best solution. This is readily available and easily assembled using tube clamps. Importantly it’s easy to replace if it gets damaged when (not if) it loses out in a fight with the buckrake.

If you want to discuss how to keep your clamp safe or any of the other aspects of silage making covered in this series – contact Jeremy Nash @ jeremy@silageconsultant.co.uk

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