Dave Lewis, from Lewis Engineering really understands the Humma articulated pick and carry crane. 10 years ago he helped with the development of his own Humma 35 Mk1 and as a result of its performance he has just taken delivery of a Humma 25 Mk2.
In 2010 DRA Group released the Humma 35 Mk1, the highest capacity pick & carry crane at the time. Humma 35 was breaking new ground in terms of design, performance and reliability, it had not been done previously and was the foundation model for the range of heavy lift pick and carry Hummas programmed to follow and reach the highest capacity whilst being road registrable. This was achieved in 2018 with the release of Humma 55 but there is still room to go further say DRA Group, by reducing the weight using composites instead of steel.
Lewis started work as an apprentice in a small arms factory in Lithgow and graduated as fitter, machinist and tool maker. He completed his special welding tickets for working in and around power stations before moving into the mining industry where he worked underground in NSW for five or six years. When he lost a couple of mates underground, he decided to start his own business.
“I started Lewis Engineering Services back in 1985 and began working for a mining company helping with some open cut mining. I then met a guy who was on his way to Queensland to put major mining equipment together in the Bowen Basin and I decided this sounded like a good opportunity.
“I arrived in Queensland in 1996 and the business got busy quickly. I found myself in a small town called Capella in the Central Highlands region and I was working for the likes of Rio Tinto and BMA. We were only a two or three man operation, working on a range of projects.
“The work we were doing constantly needed cranes and I got sick and tired of being let down by crane hire companies. We were working on specialist rebuilds of gear boxes on major earthmoving equipment, coal handling equipment, coal wash plants and applications like that. With this realisation, I purchased an XCMG 50t slew crane in 2004. With cranage now available the business expanded further and I had a team of six working with me,” said Lewis.
Lewis goes on to explain the reasons behind the purchase of his first Humma and how his relationship with the Dalla Rivas has developed.
“I had watched with interest as the Frannas were introduced to the market but I wasn’t completely happy with them. I could see there were a few flaws with their operation. In the mining sector we are almost always operating on rough and uneven ground and I could see the Frannas would break traction which results in wheel spin.
“I knew that the DRA Group had recruited Linmac Engineers with years of experience and I had always felt this type of crane needed an oscillating or swivel bearing in the articulation. When I saw the Humma included a swivel bearing that got me really interested. It reminded me of the CAT loader which is designed to operate on the most uneven of surface,” said Lewis.
Lewis rang the Dalla Rivas in WA and explained his interest in the Humma. He explained he thought they looked like a ‘tidy crane’ and wanted to know more about the articulation.
“The Dalla Rivas explained that the crane suspension worked between 12° and 15° between the front and the back axle. This is extremely important on rough surfaces, simply to maintain traction. You can do a lot of damage to your drive line if you break traction, spin your wheels and then re-engage.
“Anyway, the Dalla Rivas invited me to have a look at their operation in Western Australia and flew me over. They showed me around their factory where I test drove the cranes, I completed lifts with their cranes to 145 per cent of their capability. I was sold, we did a deal there and then and I had Humma 35-25 Mk1 delivered in Queensland and I’ve had it ever since. It’s a very tough and versatile machine.
“Everything they say the Humma can do, it can do. We had to toughen things up a little bit. I put a heavy duty bull bar on the front of the crane. Because we do smaller, heavier loads with these mining applications the crane is absolutely perfect for us. It’s a beautiful crane. The Humma 35-25 which is a 35t capacity crane does the lifts with ease without revving the engine,” said Lewis.
Lewis goes on to explain his involvement in the development of the crane. To say he encountered a number of teething problems is an understatement, he really put the Mk1 through the hoops and the DRA Engineering team found out from him that the safety factor in the booms and chassis were starting points to exceed the design limit. There were some design weaknesses in the chassis which were designed out on the Mk 2 but Lewis was able to establish the robustness of Humma 35 which has stood the test of time. The Humma 35 Mk1 was the first production model and remains today a reliable workhorse for Lewis Engineering.
“We were using the machine to make money and as we were working with the crane we were giving DRA continual feedback on areas that we felt needed attention. There were a few little things in and around the suspension. With the crane being on full air bags it drives like a motor vehicle on the road at speeds in excess of 95km but we made some suggestions around the air bag suspension, we thought they needed a little more protection. We thought the ‘lock out’ system needed to be a little more user friendly to be able to change out wear pads, it was all common-sense feedback from the workplace back into the factory. These changes are the Mk2.
“In the early days, we would be in touch with either of the Dalla Rivas on a week to week basis. They were always asking little things about the crane and I was bringing them up to speed on how it was operating. This still happens to this day.
“I’ve also been able to provide a lot of feedback to potential customers and I’ve shared my experiences with them. I’ve provided feedback regarding the capabilities of the crane, what it can and can’t do,” he said.
Lewis explains he’s been so impressed with the performance of the Humma 35 Mk1 he’s ordered a Humma 25 Mk2 which was delivered in late February.
“We requested the Mk2 have all of the electronic features DRA Engineering developed and installed on Humma 35 Mk3, digital rope compensation, dynamic load chart, height limiter and side slope derate and they said, “no problem”. The 25t Humma has a similar footprint to the 20t Franna. It is only 450m longer, weighs 23T and does not require a moveable counterweight which means it can carry 1,000kg of rigging gear.
“It has a much tighter articulation and you have basically another seven metres of boom, yes, seven metres. For us it was a no brainer. Humma is a very tidy and incredibly tough crane, it’s a crane that does exactly what DRA say it can do and more, over and over and over again.
“We’ve had the Humma 35t Mk1 for 9 years and it’s performance has been spectacular and we work in the toughest of conditions. We have clocked up 7,500 hours on it now, and this has been 7,500 hours of continuous work. There’s been a little bit of highway work but I’d say 90 per cent of those hours have been in a full on mining working environment which is notoriously tough for cranes. It’s been magnificent, we’ve got no issues anywhere, we keep to a strict regime of service and maintenance on the crane, because we have to as we are working in a coal mining environment all the time,” said Lewis.
There is continual scrutiny by mine inspectors but the crane has never let Lewis down in that regard, it’s always maintained the highest standard which is complaint and acceptable to the mines he says.
“Being nine years old, I spoke to the Dalla Rivas about the 10 year major service and was told it was not necessary as there are 20t Hummas with up to 20,000 hours and nineteen years old with negligible wear at the articulation and pivot points with no reboring necessary and bearings in good condition. Based on these results Humma now comes with 15 year or 15,000 hours OEM recommendation for the first major inspection so the Mk1 has six years before the inspection and it appears the costs will be minor,” he said.
The mines have a strong focus on safety and there are significant compliance issues with equipment operating on various sites says Lewis.
“Recently, we’ve putting in a lot of time with wheel unit change outs and the Humma has been flat out managing 16t wheel units. In our experience the 35t Humma manages this without a quiver. The geometry of the Humma helps it to be an incredibly good lifter. With the 16t wheel unit, we come in over the top of it with very low headroom with our 20t Rhino hook and special rigging we walk the crane straight in and out. In the same application the 40t Franna ‘bells’ itself out, in other words it takes itself out of the picture because it’s computer system won’t allow it to do the job,” he said.
The 25t capacity machine is going to be servicing a dragline which is currently being serviced by a 20t Franna, says Lewis.
“There have been numerous occasions when we’ve had to take our 35 tonner off its job and drive it to the dragline to perform work the 20 tonner can’t manage. We know and understand that the Humma 25 will manage this work, because it has the extra length of stick, also there is a tighter articulation.
“The Humma 25 Mk2 has a better ‘stick’ length, it’s got a greater slew range, it may only be 3° or 4°, but when you are fully extended with the boom, that 3° or 4° becomes a 1m or 1.5m. Anybody in the crane industry understands the benefit of this. The footprint of the 25t machine is the same as the competitors 20t machine, it’s only 450 mm longer and you have an extra 20 per cent capability and another 7m of stick. Why wouldn’t you buy a Humma?,” said Lewis.