Propeller Press

A customer who we have a longstanding relationship with requested a propeller press    re-fit for us ein the marine industry.

The customer supplied the framework, into which we incorporated a new valve block, fabricated a weld on bracket for gauge and a pressure relief valve and fit custom made hydraulic hoses as per technical drawings supplied by Rotec.

This bespoke piece of kit is going to Indonesia for use with straightening propeller shafts, to check propeller shafts are true.

Contact us today to see if we can assist you with your fluid power project: sales@rotec.net or 01823 348 900

Date: 8/10/19

Author: Sarka Humpolcova

 

Warship Power Units & Reservoir

After 4 months work replacing hydraulic pipework on a warship, Rotec’s engineers needed to flush the pipes to meet the required cleanliness standards. Due to a change in conditions on board the decision was made to design and build modular bespoke power units and a standalone reservoir.

Rotec have a long history working with the defence industry and specialise in bespoke design and manufacture of hydraulic power units for marine applications, amongst others.

Our team designed and built the power units using 55Kw electric motors close coupled to Berarma Vane pumps and included a flowmeter and a pressure gauge. The Berarma pumps are pressure compensated with variable flow rates. This gives the operators the flexibility to tailor flows and pressures thus ensuring turbulent flow conditions are met to maximise the cleaning action.

Electrical control panels are mounted direct to the trollies to allow ease of use

The power units are fitted with castoring braked wheels for easy manoeuvrability in tight spaces. The Rotec team also designed and manufactured a standalone reservoir, suitable for multiple applications and high volume (fluid) displacement, enabling maximum flexibility as design changes can be incorporated or removed as desired. The system includes pressure return filters which help remove any contaminants from the existing system, ensuring the pipes comply with client specified level of cleanliness.

Rotec delivered to the tight deadline, with just 1 week turnover.

Date: 26/09/2019

Author: Sarka Humpolcova

 

Case Study: Waxing Machine

This unique piece of equipment was recently designed and built at our Taunton depot. The unusual request came as a result of one of our existing existing customers, a well-known candle manufacturer, recommending Rotec to their supplier – a company specialising in the manufacture of candle wicks.

Rotec previously undertook a variety of repairs and control system projects for the candle maker and had also supported the wicks manufacturer’s machinery. Following a successful PLC re-programming project, we were asked to manufacture a waxing machine. Using old conceptual designs left by the previous manufacturer, Rotec produced an up-to-date design, new CAD drawings and a modern control system. Our team of talented engineers then successfully completed the build.

The machine is designed to impregnate and coat a continuous length of wick cord with wax and re-spool onto a new drum. The process involves a multi-pass immersion process through a molten wax reservoir followed by periods of cooling and hardening. The wax is maintained at a constant temperature, indirectly heated by hot water in a vessel located below the wax reservoir. A plc is used to control wax temperature, main drive motor speed and spooling control of the finished product. The machine is now complete and will be installed at the customer’s premises within the next couple of weeks. The machine is capable of producing sufficient finish waxed wick for up to half a million wicks a day, depending on the length of the wick required.

Rotec and the customer are already in discussions about the next project, the design and manufacture of a wicking machine designed to cut the wicks to the desired size and insert the sustainer (the small metal disc sitting at the bottom) ready to be inserted into a candle.

 

Date: 08/04/2019

Author: Sarka Humpolcova

 

Case Study: Beam trawler gets a dose of planned maintenance

Rotec recently completed a thorough service on a beam trawler, as a part of a traditional annual service on one of three local boats.

In addition to remedying the regular list of faults & based on previous experience Rotec suggested expanding the normal work list to include Planned Maintenance work. Typically this would include stripping and checking pumps, motors & valves in addition to addressing any outstanding leaks.

By carrying out Planned Maintenance tasks unexpected breakdowns of hydraulic and pneumatic components can be avoided. This was in a bid to remedy some recurring issues with steering and winching systems.

Rotec serviced the main winching system, removing and overhauling 3 hydraulic pumps, hydraulic motor & gearbox. On inspecting the drive shaft found a worn splined coupling, if this had failed thein it would have stopped the crew from retrieving their nets.

Other work included replacing a large selection of hoses, draining and inspecting the oil tank, supplying and fitting filters and a spare gear box.

 

 The engineers then stripped and repaired the pneumatic engine controls, completing a tricky job due to the controls being obsolete.

All hydraulic and pneumatic issues have been successfully rectified to customer satisfaction. This gives the skipper and his crew the confidence to go back to sea for another year.

Case study: Containerised Flushing Rig

In August 2017, the head of Rotec’s Plymouth Depot, Dave Nance, brought in an interesting enquiry from one of Rotec’s existing customers – an engineering firm specialising in work in Aviation, Land, Marine and Defence sectors.

The firm required a bespoke containerised flushing rig system for marine application. All Design work for the Container, Hydraulic & Electrical was completed in-house by Rotec, followed by a build by a team of Rotec engineers, in-house electrical specialist and a number of subcontracted engineers to help with the workload. The whole team was headed by Andy Rimes and Richard Renfree.

The project took 3 months from start to completion.

Bespoke container:

  • 6000mm long x 2500mm high x 2500mm wide
  • Tunnel design with double doors each end

2x separate Power units installed inside the container:

Each Power unit generally based upon: 4 x 7.5 Kw Motor & Pump sets installed onto a 3000 Litre stainless steel reservoir

 

  • Each Motor & Pump set producing variable flow rates from 70 L/Minute up to 170 L/Min via Electronic Variable speed Motor invertor drive control
  • Each Motor & Pump set provides Bi-Directional flushing control via directional control valves
  • Each Motor & Pump set provides pressure and return line filtration – Filtration ranges from 2 to 10 microns (Depending on filter elements used)
  • Individual contamination monitoring  for each circuit.

Custom made and designed electrical control operating system:

  • Driven via touch screen tablet control
  • Remote operating control also possible

Restoring a submersible at Aerospace Bristol

Last year Rotec were approached by the Bristol Aero Collection Trust, the registered charity behind Aerospace Bristol – a new £19m museum on the historic Filton airfield. The museum tells the story of more than a century of aviation history, from the Boxkite to the modern day, with the last Concorde ever to fly as Aerospace Bristol’s stunning centrepiece. The restoration work at the museum has been undertaken almost entirely by volunteers with technical expertise.

Rotec were contracted to help restore the CONSUB back to life after almost 60 years since it first hit water. The Continental Shelf Submersible or CONSUB is an unmanned submersible developed in the 1970 by BAC Electronic Systems Group at Filton. The remotely controlled seabed exploration vehicle was designed to operate to a depth of 2000ft., at an underwater speed of 2 1/3 knots, controlled with 1km of umbilical cable.

Harry Crick, one of the BACT volunteers explains:

“Tests were carried out in tracking underwater telephone cables and inspection of seabed features. In 1977, Consub 2 (built by British Aerospace and operated by SubSea Surveys) went into operation in the North Sea working on pipeline inspection and seabed survey. Day rates were half those of the manned submersible spread and eventually, 24h operations were achieved. This resulted in the large ROV becoming the accepted method for pipeline inspection.”

However the last surviving specimen, the CONSUB 1, was not in a working condition. It was donated by the British Geological Survey who previously used it as a display in their car park in Edinburgh.

The renovation and overhaul of Consub was carried out by Bristol volunteers at the museum.
Rotec was tasked with the design, build and supply a hydraulic power unit & electrical control system, that could be used to control the original thrusters and drill head, allowing the museum staff to demonstrate the system functionality. In order to preserve the original condition and appearance of the submersible, the original power unit was left fitted (even though it is not functional) and some of the original solid pipework routes were replicated and utilised using new tube and fittings.
Rotec built a brand hydraulic power unit which is concealed with in the exhibits structure, which will allow the CONSUB to be controlled through a control panel designed and build by Rotec, instead of through the original umbilical cords.

 

Visit Aerospace Bristol for more information, to help raise funds, book a meeting or a conference ‘Under the wings of Concorde’ or to volunteer at this exceptional new venue.

Date: 21/09/2017

Author: Sarka Humpolcova