Manufacturing excavators that can weigh up to 80 tonnes requires a surprising level of flexibility and agility in the production operations
AMS editor Nick Holt heads to Kamatsu’s plant in Birtley northern England, to find out from the company's UK manufacturing director, Paul Blanchard, the various lengths that the OEM goes to in order to keep its customers satisfied.
AMS: What’s the current capacity utilisation at Birtley?Paul Blanchard: We currently produce 1,400 units per year, which is about 50% utilisation. Back in 2007 we were manufacturing over 3,000 units per year, but the market has changed and current output reflects this. The market is increasing and we are predicting a 4% rise in demand this year.
Are you able to absorb this level of increase in demand with your current staffing levels and operations?Yes we can. We are running a number of improvement activities to increase productivity in the plant and, over all, we will maintain the current staffing level of 400 employees.What is your biggest manufacturing challenge?Our biggest challenge at present is in the finished paint area. This is because we are trying to do as much as possible for the customer in terms of preparing the machine so it’s ready to be delivered directly with all the options fitted – the bucket, the quick coupler, the seats, etc. This requires a convergence of operations and sees a wide variation in the work content across the different sections of fabrication, paint and assembly for each individual machine, so scheduling is always being revised. This challenge increases as we introduce more options for our customers.
Do the export models add more variants?They do. For example, if Komatsu are exporting to Scandinavia the customer usually requests high-spec machines with heated seats, pre-heat systems, LED lights, etc. But there are also variations unique to UK customers; eg. vandal guards. We also offer custom colour schemes to match company branding, which are very popular in Holland and Germany.
Do you have to produce machines to meet different emissions regulations in various global markets?We are fully Euro stage 4 compliant so this covers European exports. For Turkey and Morocco we offer a different emissions control package, as they don’t need to meet the Euro stage 4 requirements. In these areas it’s more down to the fuel quality that’s being used, so we can offer an earlier version of the engine.
The assembly line moves slowly but work content is high at each station
The 20-tonne models are your most popular range. How many variants do you produce for this range?That’s a hard question to answer; there are a huge number of options, which will depend on the application the customer needs it for. On a basic level we offer four arm lengths, three undercarriages (the NLC, standard and long undercarriage), [with] up to five different track shoes for each of those variants. There are a multitude of smaller options covering connectors, lighting, cameras, interiors, etc. We will also build machines for specific tasks, such as demolition.
Would you build a machine for a specific application not be covered by your options list?Yes, we can do that. The customer has to submit a RONA (request of non-specific attachments). We will do an assessment from both a design and cost point of view, to determine if it’s feasible.
Do you operate a just-in-time parts delivery system?We don’t operate just-in-time in terms of the parts delivery as we have a global supply chain for this plant. Also the volumes we produce, plus the variety of options we offer and manufacture, make it impractical. For parts coming from Japan and China we have up to a 130-day lead time, so we carry a high level of parts inventory to ensure we can offer the customer the flexibility in production. We will produce a customer’s machine three weeks from the day the order is placed. It’s a very different approach to that of mass producing cars.
How closely do you work with your suppliers? How far are they integrated into Komatsu’s operations?We do have a very close working relationship with our local suppliers. We invite them to in-house events such as our ‘Techno Olympics’ where we run competitions to find the best fabricator, assembler, etc. And they take part in this. We hold an annual supplier’s day where we set out our production plans for the year based on market predictions and discuss any planned expansion. I probably know most of our local supplier [representatives] by name. Our steel supplier for cut parts visits the plant on a weekly basis to meet with the production managers to ensure there are no problems. We have strong ties with Cummins who provide our engines and we have been working with some of our suppliers for more than 20 years.
Komatsu manufactures many of the components used on the excavators built here, but how many major external suppliers do you have?We have around 50 global suppliers working with us. Previously it had reached 100 suppliers but this was becoming unmanageable so we reduced the number as part of a rationalisation programme after 2007 as the volumes were falling at that point.
How much local content is featured in the machines produced at Birtley?It’s not high, perhaps 20% of the parts are sourced from UK suppliers. Komatsu takes a global view, in that it will locate a supplier for particular components or systems that will supply the global manufacturing network. So much of our parts supply is shipped into the UK via the Port of Tyne, which is a relatively short distance from this plant.
What’s the percentage of automation across the plant?We don’t have any automation in terms of robots in paint or assembly. The shape of the parts makes it very difficult to use this type of automation and it would require a high level of investment. With regard to welding, we are increasing automation here and the two new global Komatsu robots we recently installed now perform about 95% of the welding operations on the track frames. We have older robots for welding the booms and these cover 80% of the welding in this section. This is an on-going investment programme and next year we want to install a new global robot for welding on the high-reach excavators. This is a completely manual operation at present and adding automation will improve productivity in this section.
You already produce a wide range of machines but are there any plans to add new models?The hybrid machine is the most recent addition and we will be bringing in the new ‘intelligent’ LCi machines. Our main production line can handle any variant between a PC210 to a PC490. The larger machines [PC700 and PC800] are much lower volume and produced on a separate line that is essentially a static assembly operation.
The LCi machines must feature a lot of extra electronic content. Has this had any impact on the assembly process?Most of the sensors are already built into the [hydraulic] cylinders, but there is a lot of ‘off-line’ work in terms of setting up and calibrating the sensors. The level of technology in these machines has increased significantly and the assembly operators have had to undergo a lot of additional training in electronics and computer systems. We have seen this need across a number of areas, such as design, quality and field support. It’s a different requirement for the mechanical engineers, much more a move towards electrical engineering. It is a challenge but we have been training with experts from Japan, who are working here for two to three weeks at a time, training staff and sharing expertise and experience. The aim is to create a team of [electronic] experts here at Bartley. This is the direction the machine development is taking, with even the high-reach models featuring a very sophisticated load-sensing system that allows the operator to work at the maximum reach, and this takes a lot work to calibrate the system. We are also adding a new 360° camera system to the hybrid machine initially, and the set up of the cameras is quite challenging.
How have you prepared for this?We have a lot of internal training and the people here have an excellent understanding of the product we build and have proved willing and able to meet the challenge of the new technologies; this attitude is very much part of the Komatsu culture. We have a very low staff turnover here; many of our employees have been with us for more than 15 years, which means we retain the depth of experience.
MAKING IT BIGProduction at Komatsu’s Birtley plant currently puts out six to eight machines per day of those in the 200-400 model range. Output of the larger 700-800 machines stands at one per week.
The plant is divided into three main areas: fabrication/machining, paintshop and assembly. Seventeen Komatsu welding robots perform most of the major welding operations in the fabrication area. This represents the highest level of automation in the plant at around 85% and it is set to increase as the company invests in upgrading the weld robots; recently two new global robot welding cells have been installed replacing three older ones.
Public relations officer and former paintshop team leader, John Lawson, explained that the two new robots have increased productivity and that further investment will see upgrades to the track frame welding cells.
There are still manual welding operations where the pre-cut and shaped steel sections for the booms, track frames and revolving frames are placed in jigs and the preliminary welding takes place before transferring to the robot cells. As each operation is completed the operator responsible stamps a number into the surface of the component to indicate that stage is complete.
Moving metalThis is truly heavy engineering with the whole plant covered by various overhead canes to facilitate the movement of components from one stage to the next. There are four huge CNC centres that precision machine (to tolerances of 0.03mm) the various pivot points to locate the booms, arms and hydraulic cylinders before they are sent for painting. The paint facility is completely enclosed and located within the plant. The excavator sections for paint are attached to an overhead conveyor and then transported through each stage of the process. These stages include a phosphate pre-coating and a single topcoat (a catalyst and colour mixed as the paint is fed to the gun) that is applied manually. To reduce waste and minimise any overspray an electrostatic system is used, which ensures complete coverage of all areas of the part. The finish is then carefully inspected for any defects.
Clean room investmentNumerous sub-assembly stations, providing driver cabs, hydraulic and electrical systems, feed the main assembly line. The main line moves at a stately 115mm per minute with operations at each station taking around 80 minutes. Recent investment includes £400,000 ($521,720) for an engine clean room. This has been added for assembly operations on the new hybrid engines. A key task is the mounting of the generator to the hydraulic pump - the generators feature very strong magnets that could attract metallic dust particles so cleanliness is very important.
The engines for the 20-40 tonne models are supplied by Cummins as part of a joint venture with Komatsu. Cummins build the engines according to Komatsu’s design and specification. The room is also used for dressing the engines with the necessary ancillaries.The heavier sections (arm, boom, track frame) are fed in from side sub-assembly areas using heavy-lift cranes and it’s an impressive and smooth operation with deft handling of such heavy and awkward parts.
Quality checks are detailed and conducted through out the assembly operation. A good example of how thorough the checks are can be seen in the sub-assembly area for the booms and arms. Here the hydraulic pipes and cylinders are attached and connected, and each connection is checked three times; firstly by the installer, then by his colleague at this station and finally by member of the quality team, going through every connection and fastener checking the correct torque has been applied.