As easy as LPG
September 1st 2004

Always the clean burn option when it comes to IC forklifts, developments in LPG technology now mean it can be used in applications traditionally seen as purely the domain of electric trucks.

Charlotte Stonestreet (editor of IP&E’s sister materials handling journal H&SS) spoke to Stuart Goates from Calor Gas

Although you may not immediately associate a company like Calor Gas with materials handling, with a market share reckoned to be just over 50%, when it comes to supplying LPG for forklift trucks, there’s not much that Calor Gas doesn’t know about this particular sector of the industry.

Calor first became heavily involved with the forklift truck market in the early 70s when the company was working on the development of gas powered engines at its test laboratories. The research was applicable across various ranges and industry sectors and, according to Stuart Goates, Calor’s forklift truck national sales and sales development manager, the forklift truck market was a big part of this. Of particular note, Calor was instrumental in the development of the EPS two-way catalytic converter the first two way cat in the UK. Now more than 30 years on Calor is still heavily involved in the materials handling industry, from continuous technological developments to the overall promotion of LPG.

Choosing LPG

In today’s market place, Goates cites the high price of warehouse space as one of the main contributing factors behind many UK businesses choosing to run their fleets on LPG.

Warehouse space per square metre in the UK is some of the most expensive in Europe. As a result you tend to find that companies are looking to utilise their warehouses a lot more, so instead of using single or double shift, they implement triple shift operations.

And this is where LPG really comes into its own. In contrast with electric trucks, which typically take around eight hours to recharge, an LPG truck can be refuelled in about three minutes, making true 24/7 operation viable. It also eliminates the health and safety risks associated with battery changing.

As well as saving time on refuelling, running a fleet on LPG can save valuable storage space as there is no need to have a special area set aside inside a facility for battery charging. Whether cylinders or a bulk tank are used, LPG can be stored outside the actual warehouse.

“With electric fleets, if you are not regimented about recharging you either have to have spare batteries sitting around or you have to have a couple of spare trucks for back-up,’ comments Goates. He goes on to say that changing from electric to LPG has enabled many of his customers to reduce the number of trucks they need in their fleets.

Further benefits of LPG trucks come from the fact that they are suitable for use both in and out of doors, increasing flexibility. They also have very low emissions, particularly when compared with diesel alternatives.

At the moment in the UK there is no one piece of legislation that specifically covers the emissions from forklift trucks. Generally, this is covered by EH40 Occupational Exposure Limits, but according to Goates, with the latest three-way catalyst technology LPG hardly registers on this scale at all.

One of the latest health and safety concerns as far as truck emissions are concerned is NOX, says Goates. Up until a few years ago this carcinogen wasn’t even measurable. The beauty of LPG trucks is that, when fitted with a catalytic converter.

you can get a 95% reduction in NOX. On the other hand, it’s not commercially viable to remove NOX from a diesel operation.

Goates also points out that, although on paper the emissions from a diesel truck may seem favourable, as the truck ages and the engine starts to wear the emission levels will become higher.

Less engine wear

Indeed, by its very nature, LPG is a high octane, clean burning fuel, something that, says Goates, results in less carbon build up on engines, less oil contamination and less overall engine wear.

An LPG truck fitted with a three-way catalytic converter and closed loop engine control system continuously changes its fuel to air mixture so that it always gives an optimum burn, says Goates. Basically, if there is not enough oxygen in the mixture, the efficiency will be adversely effected and harmful emissions will increase. To ensure optimum burn is achieved and emissions kept to a minimum, the latest systems adjust the fuel mixture 1000 times per second.

The latest developments in three way catalytic converters and closed loop engine control and the resultant emission reductions are also enabling LPG trucks to be used in areas that were, in the past, purely the domain of electric trucks. This is particularly relevant in the food manufacturing industry. Although Goates admits that no IC engined truck will ever be suitable for use in the actual food production areas because of hygiene issues, once food is in its primary packaging he sees no reason why an LPG truck cannot be used if the right emission reducing equipment is fitted.

Although there is no doubt that, pence per litre, diesel is still much cheaper than LPG, there are many other factors that need to be considered that will have a dramatic effect on the overall costs of running a forklift fleet. For example, some companies will only accept packaged goods that are completely free from any kind of contamination, so soot from diesel trucks can prove very costly.

Health & safety benefits

There are also the longer term health and safety benefits to employees and consequently employers that arise from reduced manual handling (through the elimination of battery changing) and favourable emissions.

Goates also points to the initial capital outlay. He estimates that to put the latest three way catalytic converter with closed loop engine control on an LPG truck costs in the region of £1500 to the customer, whereas a two way catalyst and soot filter fitted to a diesel truck will probably cost nearer £5000 extra.

If it’s a yard truck, purely working outside all the time then, yes, you are going to go with diesel because you do not go into any sensitive areas. But if it’s an in and out operation or permanently inside, that’s where I feel LPG really stands on its own merits, emphasises Goates.

And it’s not just the large fleet users that can benefit from running their trucks on LPG. Calor has a growing number of customers that run just one or two units.

The key in these cases, feels Goates, is the simplicity there’s one LPG bottle on the back of the truck and a spare one waiting to be swapped into place when needed.

When this happens, the customer orders another bottle to replace the empty one.

Simple and cost effective, this means the customer does not have to worry about battery changing or charging, or derv storage, which requires double bunded tanks.

Although for larger users Calor will arrange a kind of ‘milk round’, where empty cylinders will be collected and exchanged on a weekly basis, if you are running anything from three trucks upward it is probably worth thinking about installing a bulk tank. Not only can this result in a pence per litre saving on the LPG, it also eliminates any manual handling.

According to Goates, in most cases installing a bulk tank is a fairly straightforward exercise. A concrete pad is required something which most facilities will already have along with a 240V electricity supply for electric dispensing and some protection for vehicles. In fact, around 90% of Calor's installations now make use of tanks that are totally prefabricated off site and arrive complete on a skid unit, ready for commissioning.

Installation advice

Calor will advise customers on what exactly is required for each site to comply with Code of Practice 1, Part 1 on the installation of bulk vessels that has been drawn up by the HSE in conjunction with the Liquified Petroleum Gas Association.

One of the latest installations at the Hayes facility for B&Q in Doncaster demonstrates the company’s abilities in turnkey installation.

Perhaps Calor’s most state-of-the-art project to date, the installation has been designed to overcome every eventuality.

There are three refuelling points on this system two at the main warehouse and one 600m away at the tank farm so if anything ever prevents refuelling at the warehouse, it can still take place at the tank, explains Goates. There are two refuelling points at the warehouse to prevent the trucks from having to wait to be refuelled, but it also means that if something happens to one, you still have the other that can be used.

Like all of Calor’s bulk tank projects, this uses safety breakaway couplings that will shear and cut off the gas supply should someone try to drive the truck away during refuelling.

Although in general the technology seen in the LPG forklift market is pretty old (Goates refers to it as ‘Cortina’ technology), Calor is always at the forefront of any new developments in the area. One example of this is the use of telemetry whereby Calor is able to remotely monitor via a telephone line how much gas a customer has left in their bulk tank. As well as enabling Calor to minimise routine deliveries and avoid emergency deliveries, this can prevent customers running out of gas and losing truck up-time as a result.

Other new developments in the market mean that Goates is confident that the use of LPG forklifts will continue to grow. For example, Narrow Aisle and Translift now offer articulated trucks that run on LPG, and Combilift is making waves with its LPG multi-direction units. There’s even talk of an LPG forklift engine with a fuel injection system. And as LPG becomes an even cleaner fuel option, it will continue to make in-roads on the traditionally electric warehouse market.

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