Stage Technologies provide testing tower for rigger safety10 March 2011
Across high tech manufacturing, pharmaceuticals and food production, crane manufacturers have to meet tight specifications for clean room cranes. Nicole Robinson and Will North report
UK-based manufacturer Street Crane builds cranes for use in clean rooms for a range of customers, from aerospace manufacturers to nuclear submarine maintenance firms, high tech laboratories to food processors. Managing director Andrew Pimblett says, “Cleanroom specs create huge problems for crane manufacturers. A crane isn’t the sort of equipment you can put in a box, it has to travel over the whole area.
“Generally, cleanrooms are defined according to classifications in ISO 14644-1. The most common cleanroom situations for crane manufacturers are found in high tech manufacturing, such as for jet engines and silicon chips, where particles must be kept out of the product being manufactured. Other situations are the food and pharmaceutical industries, where different sets of rules apply.
“At one end of the scale, the problem is loose article containment. We’ve come across this problem in military and nuclear applications. One example was DML, who service nuclear submarines. They needed to have fully redundant 100% loose article containment, so every nut or bolt had to be secured to the crane by a wire, so if they came loose, they would not be dropped.
“When you get to containment of smaller particles, ISO 14644-1 categories are classified according to the size of particles and number of particles per cubic metre of air.
“The problem for crane manufacturers is that a crane needs to run on rails. As it does, small particles of rail come off. The same thing happens with chain or rope used to lift the hook.
“In cases like that, it’s not a case of making a crane that complies with the standard exactly, but putting the crane in the cleanroom so that the room complies with the standard when it needs to. Often, the cleanroom can be designed so you can lift things in and out, move the crane out of the way, and then use the room as a cleanroom.
“There are some types of cranes that comply fully, but these can add serious costs. When we see one of these specs, we always say, ‘Let’s talk to the customer’. Nine times out of ten, you can find a way to do the job without meeting the full specs. Engineers often have a tendency to overspecify. When you talk to them, they realise they don’t need to. The purchaser and the supplier have to reach an understanding of what is actually needed, because of the costs of full compliance.”
In Switzerland, German-owned international manufacturer Demag Cranes & Components has worked with specialist manufacturer Högg to build a crane suitable for working in clean room conditions. Högg builds specialist products for the semi-conductor, vacuum and solar engineering sectors, using a cleanroom to avoid contamination. Högg meets ISO 14644 requirements by multiple filtering of its air and ventilating the room with overpressure. Workers wear clothing appropriate for the application. The clean room can only be entered via adhesive foot mats and an air lock.
Högg invested in two double-girder overhead travelling cranes from Demag Cranes & Components, using the KBK crane construction kit. One of the cranes is used direct in the clean room for the assembly of components, of which some are very voluminous and heavy. Demag utilised the KBK II profile section for the crane and its track, which is approximately 30m in length with a 5m span. The load is picked up by a DKES chain hoist fitted with a single hook. Högg chose a cable-connected control pendant for the controls. Modifications include clean-room grade paint, enclosed chain systems and encapsulated electrical components.
Some of the most rigorous requirements come from the pharmaceutical sector. Speaking with several US manufacturers of stainless steel products used in the pharmaceutical marketplace, it emerges that while many end users—major manufactures like Merck, Eli Lilly and Pfizer—have stringent requirements developed and followed in-house that stem from current Good Manufacture Practice (cGMP or GMP), there is no specific FDA requirement for sanitary cranes. Therein lies a significant difference with other industries.
Matt Downing, director of sales and marketing for David Round, deals with both the pharmaceutical and food industries. He points out that enough E. Coli outbreaks, food recalls and other public scares have happened for Congress to overhaul food safety guidelines. President Obama signed a food safety guidelines bill into law in January.
Dane Oliver of Carpenter Crane Hoist works with the pharmaceutical and high tech industries. He tells of a semi-conductor client that appointed Carpenter to build a lifting system for a piece of optics, and had very specific molecular requirements. “We helped them design it initially and they tried to buy it somewhere else, but they came back to us,” he explains. “They thought our prices were too high, yet they’re back dealing with us because they thought we were the only ones who could do it.”
Without the food industry’s federal guidelines, and unlike the tech industry’s precautionary spending to prevent expensive downtime, there is the pharmaceutical industry. Stainless steel crane manufacturers observe that compromises have been made on the finish or quality of a product, to cut costs.
Generally speaking, lifting products will be used in a clean room or an area with similar restrictions and call for stainless steel cranes rather than a standard carbon steel painted crane. The finish must be smooth, and all welds ground down, leaving no crevice for bacteria to build up. It’s a matter of fact; these cranes are expensive. And often that’s a hard pill to swallow.
There are two technical challenges for crane and hoist equipment for the pharmaceutical industry, the product’s surface finish and its ability to be washed down daily, or several times a day. Each application is different depending on whether the pharmaceutical product is a liquid, powder, pill, etc., and how the cranes and hoists are cleaned—whether washed down, wiped down or removed for cleaning.
“A lot of [pharmaceutical crane maintenance] has to do with the cleaning process. Most of them use either a chlorine solution or disinfectant solution and some of those can be very caustic,” says Oliver. He explains most of the cranes in those environments have to be stainless steel, including all the fasteners and other elements.
And not all stainless steel cranes are created equal, there are different grades, and to meet clean room standards, everything must be smoothed, sealed and polished so that nothing can stick to anything, anywhere.
“And there are very few cranes in the marketplace that can boast the ability to do that,” says Tim Carney, owner of TnT Handling USA. “There have been compromises made [within pharmaceutical purchasing] with regards to crane finishes in order to bypass the costs associated with extreme GMP crane systems that offer high polish welds, high polish finishes and the cranes overall.”
Oliver says that is his biggest problem, too. He explains that other manufacturing companies don’t have enough experience, noting Carpenter Crane Hoist has its own clean room in-house for manufacturing. “They don’t know what they don’t know. And therefore we get customers that are told that [a crane company] meets a requirement that they don’t. That’s our biggest problem that people on the market don’t know what they’re selling.”
Carey explains, “I think in a lot of cases now [pharmaceutical companies] are outsourcing lower spec, standard spec product. And in many cases I think, unless it involves a huge engineering project, they’re doing this mostly through local distribution. And I know this for a fact because I happen to deal with the local distribution.”
That is in comparison to the applications overseen by architecture and engineering firms that specify equipment for projects, and drive up demand for stainless steel equipment.
And that’s not to say end users are not concerned. Tim Burns, president of Ergonomic Manufacturing Group in Philadelphia says he’s within a two-to-three hour drive of many of the pharmaceutical manufacturing facilities, which often send an engineer and a quality inspector to make sure the equipment is up to their standards.
“You may literally have to grind a weld so smooth that you can’t even see it,” he explains. “It’s a lot more time in the manufacturing process and it’s a lot more detail-orientated because you have to go to a certain level. Most of the times when we’re doing something for pharmaceutical cranes we have someone from the facility come out.”
The FDA requires a certain level of cleanliness, and not specifically that a stainless steel crane be used (though that day is not far away says Downing). More pharmaceutical companies are aware of what’s available and what’s necessary. “I don’t know what instigated the migration that we’re seeing, but I think their manufacturing processes are requiring a better cleanliness level,” says Oliver. “They’re finding contamination off of the traditional lifting systems.”
Another big driver is OSHA introducing more stringent lifting restrictions. For example, Ergonomic Manufacturing Group started in the ‘80s by selling its VacuHoist and moved into crane manufacturing in 1993, and then into stainless steel crane manufacturing in 1995 because so much of its business was based around the food and pharmaceutical industries.
Starting as a specialty niche, the light weight lifting sector has developed over time to include many capacities up to 2t, as the company’s distribution network expanded and demand for stainless steel lifting equipment increased.
Over the last 20 years the market for pharmaceutical applications has changed quite a bit, says Burns. OSHA has introduced regulations for repeated lifting and other back injuries—that has helped business a lot, he points out.
There is a tendency to think, ‘pharmaceutical, that’s lightweight’, he says. “Light weight is a relative term. People were picking up 80lb–100lb boxes when we started. Now those plants have self-imposed rules where they won’t allow them to pick up more than 25lb boxes.” Despite the increased business provided by lifting regulations since Burns began working in the pharmaceutical market some 20 years ago, it’s slowed a little bit, he says, a likely side effect of consolidations. Looking at the ever-changing landscape of the marketplace it’s no surprise.
The pharmaceutical sector faces the same problem with particles created by friction that Pimblett describes. One British manufacturer, Hoist UK, has come up with a solution using blondin cranes fitted with fibre belts. The company explains that normal cranes are fitted with chain hoists or wire rope hoists which require metallic chains or ropes to be lubricated. This can contaminate the clean room environment.
Instead of chain or rope, the lifting belts used in Hoist UK’s BH series of electric belt hoists are constructed with fibers, a form of polyethylene which is up to 15 times stronger than steel, and up to 40% stronger than other man-made fibres.
The belts used on these specialist cranes have a minimum breaking load of 8t and in this particular application Hoist UK uses a safety factor of 12:1, with no lubrication required and no pollution or contamination to the clean room environment.
The cranes can be mounted from steelwork in the clean room or can be free standing in a fixed or moving arrangement using air cushion technology to allow the structure to be moved across the floor without having contact with the floor.
Hoist UK’s custom clean room cranes are currently available for single cranes up to 6.3t lifting capacity with a 10t version coming soon. A system has been recently produced to lift 20t using four individual 5t cranes with a control system to ensure fully synchronised lifting between the four units.