Powers of persuasion

Forklift trucks, notably the counterbalance variety, have long been considered the handling equipment of choice for manufacturing sites of all sizes and sector. The choice of diesel, electric or gas power has traditionally been driven by working environment - and each power source has found favour with particular sectors. But as technology has developed, so too has the range of applications in which each fuel type can now be used. Figures released this month by the British Industrial Truck Association (BITA) show an increase of 24% in sales of forklift trucks during 2010 - although that's from a low base in 2009, when the truck market was hit very hard. Nonetheless, the type of trucks being sold does underline the general economic data in the news, with counterbalance trucks doing particularly well. BITA says engine-powered counterbalance trucks saw the biggest increase last year, with orders rising by 30%. This equates to a rise of 29% for diesel and 32% for liquefied petroleum gas (LPG). Their electric-powered cousins also fared well, recording a 22% rise. In the current climate, when forklift fleet managers are doing everything possible to maximise efficiency, it's perhaps not surprising that fuel type is a key consideration. BITA's technical consultant Bob Hine agrees and says the choice of fuelling options has to accommodate the enormously varied roles that lift trucks perform. "Industry's strategy is not about moving to a single 'most efficient' fuel source, but instead about maintaining processes of continual development and innovation to improve efficiency and performance in current sources." Take electric, for example: there will always be a demand for the quiet, clean battery-powered forklift. However, one of the common criticisms is the need for slick battery management, if the trucks are to operate at maximum capacity. Effective battery management - and an efficient charging regime - is essential for long battery life, as battery manufacturer Hoppecke points out. Indeed, the chargers are the key to maximising electric truck operation. Hoppecke has patented its Trak air battery system which can bring significant savings for forklift fleet managers. It has some impressive stats: as well as reducing battery temperature levels by around 10¡C, Trak air takes battery filling down to four or six times a year, reduces gassing and can lower electricity use by more than 30%. Charging time is much faster with a microprocessor-based high frequency charger, and water use is cut by up to 70%. The system works by introducing air into the battery at the main charging stage. Rising air bubbles circulate around the electrolyte and prevent acid stratification. This method of mixing sulphuric acid by in-blown air is efficient and means there's no need for weekly equalising charges, often called for with other types. But more than that, the charge is faster so batteries are available sooner - and Hoppecke has an automated selection system that sounds an alarm if a driver tries to take the wrong battery. For some buyers, the risk of losing valuable truck uptime - and the possible knock-on effects to production - is one of the concerns with electric trucks. In response, Hoppecke cites the case of an automotive manufacturer which needed to achieve 98% uptime for its tow trucks taking up to six tonnes of car parts from loading bays to production lines. The manufacturer wanted to extend the operating time, too, from a single four or five hour shift up to 12 to 18 hours. Despite reservations about whether this would be possible, its fleet is now working from 6am to midnight using the high frequency Trak air system. It has cut battery charging times from eight to five hours. Many of the benefits are backed up by BITA's Bob Hine. The latest generation of high frequency chargers, he says, use smaller, more efficient components with lower losses. They typically require 5 to 10% less power per battery recharge, and AC input currents are approximately 30% lower than those drawn by traditional regulated chargers. "The resulting lower running costs mean high frequency chargers can usually repay their slightly higher initial acquisition costs over a five-year lift truck operating lifecycle," says Hines. HF chargers are also much smaller and lighter - important when giving over precious production space to a charging room. In the UK, electric trucks still out-sell internal-combustion powered trucks by a ratio of 2:1. However, within the IC-engine category, LPG is fast catching up with diesel: last year's figures show just over half (53%) were diesel, with 47% LPG. "LPG is now being considered more seriously as a cost-effective, 'clean' alternative to both diesel and batteries, particularly for vehicles that operate both indoors and out," says Hine. If fitted with a three-way filter, for example, LPG engines emit no lead or soot, and emit a low level of PM10 particles. They also have low CO2 emissions. Also, supplier Shell Gas points to the versatility of LPG trucks, with their lifting capacities rivalling diesel and the ability to work indoors and out, which can be vital if the equipment needs to be used in different areas of the site. With LPG, the choice of bulk tank or cylinder supply has changed in recent years, too. Whereas a manufacturer would need a fairly sizeable fleet in the past to justify a bulk tank, now they need only have as few as five trucks working on a single shift - or even fewer if they work around the clock. BITA's Hine says that LPG is now a serious rival for diesel and electric. "LPG is more cost effective than diesel if compared on a pence per litre basis, and there is no opportunity to pilfer stored fuel to use in road vehicles." Diesel truck users will be only too aware of the dramatic rises in the price of diesel, but despite this, it remains the fuel of choice for those forklifts used outdoors only. At Pork Farms Palethorpes, electric-powered trucks are now few and far between and the site has moved across to LPG for its Caterpillar counterbalance trucks. Pork Farms was established in a shop in Nottingham in 1931 - today, it employs 2,000 at three UK sites. The 600-strong Palethorpes site in Market Drayton operates around the clock, producing sausage rolls and other savoury snacks. It also has ambient and chilled warehousing on site. Supply chain manager Dave Bradley took the decision last year to change the counterbalance trucks from electric to LPG. Key issues, he says, were reliability and the need to maximise truck uptime: "In my experience, with electric trucks the batteries and charging systems need to be carefully maintained, or they can fail on you at the worst possible time." With LPG, he adds, as long as the gas is delivered by the supplier, trucks can - and do - operate 24/7. It's not just a question of truck uptime, however. "If you remove the need to recharge batteries, you remove the health and safety risks associated with battery handling," he says. A couple of hours' training for the operators taught them the safety principles of LPG refuelling, plus what PPE to wear. Pork Farms Palethorpes still uses two electric trucks in the chilled storage area. It tried gas trucks here but, says Bradley, the lack of air movement meant that the build-up of fumes - though not harmful - was unpleasant for the operators. "It wasn't about safety, since the fumes were non-toxic, but we couldn't easily improve air flow in the fridges, so we decided to revert to electric trucks," he explains. It also has two reach trucks in the packaging area. As part of the fleet renewal process with supplier Briggs Equipment, the forklift truck distributor was able to recommend attachments to enable Palethorpes to reduce the fleet size and benefit from more truck multi-tasking. The three LPG vehicles are used to unload raw material and to assist with engineering tasks around the site, but a key use is the removal of waste from the site and the attachments are now enabling all three trucks to help with this vital role. The gas supplier for the site is Telford-based Budget Gas, a subsidiary of Calor. A small bulk tank is monitored by the gas company and refilled every two to three weeks. While bulk tank supply has typically been out of reach for sites with as few trucks as this, Pork Farms Palethorpes was able to strike a deal with Budget Gas for the tank: "It was important to have the bulk tank as there are still manual handling risks for operators if they're moving cylinders. Equally important, there are cost implications - with bulk supply, you use all the gas you buy. With cylinders, drivers inevitably return cylinders which are not quite empty so you're effectively giving the gas away." Bradley says he has yet to carry out a full evaluation of the cost of LPG versus electric: "The key factor for me was value of uptime and removal of manual handling risk." For him, using LPG in forklifts is all about best practice: "I'm passionate about maximising productivity and being as lean and green as possible. LPG ticks all the boxes."