Plymouth-based MSubs is a manufacturer of manned and unmanned subsea and surface vehicles with customers ranging from wealthy individuals who buy their products purely for pleasure and the world’s navies who use them for more serious pastimes such as remote mine detection, systems checking and covert operations. The submarines manufactured at Plymouth range from small unmanned decoys, through to large manned craft that can stay submerged for up to 48 hours at a cruising speed of five knots and provide life support for up to 240 man hours.

With each of the larger submarines taking up to 18 months to design and build, and with increasing demand, the company relocated to new premises in mid-2010 At the same time it also undertook a review of its manufacturing processes and merged with precision engineering company Sam Brown Engineering, which was its next door neighbour. This merger brought with it a capacity to machine smaller components on a range of ProtoTRAK controlled turret mills, which had been purchased from XYZ Machine Tools over the previous 13 years by owner Sam Brown.

However, with an increase demand for larger components such as hatches, propeller and directional fins, MSubs found itself having to subcontract more and more work. This outsourcing of work was causing both logistical and cost issues; therefore the management team took the decision to review its entire machining capacity. The result of this review was the decision to bring all machining in-house, which required additional investment in larger capacity machine tools.

Having already developed extensive experience of operating machines with the ProtoTRAK control system MSubs looked to Burlescombe-based XYZ Machine Tools to provide the additional capacity it required and to assist it in reducing manufacturing costs. “The cost of sub-contracting these larger and more complex components was becoming very restrictive,” says Manufacturing Supervisor, Sam Brown. “For one particular hatch component we were being quoted £50,000 each, and we had 20 to machine. This meant that the justification to buy the two new XYZ machines was a relatively straightforward one, with the machines paying for themselves in a very short space of time.

“Our experience of the ProtoTRAK control system also meant that we were operating in a very short space of time, producing quite complex shapes and contours. The existing employees had a refresher course on the control system and those new to it had just one day, which was more than enough for them to be confident in programming and operating the machines.”

The machines purchased by MSubs were a ProTURN SLX 555 lathe and a SMX 5000 bed mill, both of which are currently the largest machines of their type in the XYZ portfolio, although larger machines are due to be added to the range in the coming months. The XYZ ProTURN lathe chosen by MSubs has a 3 metre bed length and a swing of 900 mm in the gap (560 mm over the bed), and with its 11 kW, 30 – 1800 revs/min spindle is capable of significant metal removal. This machining capacity is enhanced by the single, solid ribbed, cast iron base with extra wide vee and flat bedway design. The SMX 5000 bed mill was also purchased for its size and versatility, providing X axis travel of 1524 mm and Y axis travel of 596 mm. In this case the standard Z-axis travel of 540 mm was enhanced with the addition of a riser block, to enable oversize components to be accommodated.

“Having the two larger capacity XYZ machines on-site is a major advantage as we have total control over our manufacturing. Design changes can be taken in our stride with any changes being made either at the machine or via transfer of DXF files. For a relatively low cost investment we have greatly enhanced our manufacturing capacity and both machines have performed exceptionally well even when we have pushed them to the limit and in some cases beyond. The versatility of the bed mill has enabled us to machine parts that in theory are beyond its capacity and it is similar case with the ProTURN lathe, where we have asked it to machine diameters and lengths that in theory it shouldnÕt be able to do. This is testament to the rigid build quality of the machines.”

(Above) The team at MSubs with the finished product.

(Above) One of the Subs in action.

(Above) The XYZ ProTURN SLX 555 at MSubs is helping to reduce manufacturing costs.

(Above) MSub’s XYZ SMX 5000 ProtoTRAK equipped bed mill is proving highly versatile when machining oversize components.

(Above) This Duplex stainless steel hatch is machined complete, in-house, on the two new XYZ Machine tools.