Engineering, Freight Rail, Passenger Rail, Rail Supply, Technology and IT

Significant evolution in overhead wire roll out and tensioning methodology

The concept of running dual overhead wire under final tension parameters has become an Australian reality, with the commissioning of the new Manco Rail WT2020 tensioning technology.

Manco rail specialises in providing custom built rail and road/rail equipment for rail electrification construction and rail maintenance contractors. Its WT2020 tensioning consist was recently hired by the CPB Contractors and Lendlease joint venture delivering the Caulfield to Dandenong Level Crossing Removal Project.

The unique new consist was used extensively throughout the project, with expectations of exceptional productivity and total reliability being fully achieved and maintained throughout its use, according to Manco Rail boss Bryan Black.

“While such tensioning is a recognised method in Europe, the uniqueness for this project and also globally, is that the two tensioning components are mounted on two 300HP Isuzu FVZ Road Rail vehicles locked together forming a single centrally controlled consist,” Black tells Rail Express.

“This is a significant variation to the European tensioning units which in the main, are wagon mounted and hauled generally by an electric or hydrostatic-diesel locomotives.”

Engineering design for the consist required a significant and in-depth interface between the RRV manufacturer, Manco Rail, and the tensioner supplier, OMAC of Italy.

“The electronic control systems posed the biggest challenge,” Black explains. “The RRV CAN bus and management needed to interface with the tensioner programmes to avoid any possibility of over or under tensioning which would clearly negate the benefits of such a consist.”

To obtain the required traction and power, special reduction boxes were installed in the two RRV power trains, enabling the optimum vehicle engine torques to be achieved within the desired track speed range of up to 6km/h. Without these, the required track speed of 6km/h would be achieved at little more than an idle, well below the HP and torque requirement.

“The next issue to address was to ensure that the RRV mass would be sufficient to ensure there was adequate weight to maintain traction on grade and when subject to a wet track surface.

Using special cross tread, ‘super-single’ drive wheels and the ability to adjust the down force via variable custom air suspension, constant loading is maintained and held during all travel functions and stopping without altering the wire tension.

Both of the RRV’s Engine Control Units (ECUs) are interfaced within a central control cabin, which also enables full operation from engine start/stop and failsafe braking. These values are fed into the two capstan PLCs where the operator, after setting the two desired tensioning parameters, has the option of preselecting either manual or automatic functions.

Manco Rail says the consist offers a field of tolerance of +/- 8% under static hold, or +/- 10% dynamically based on full scale values. Full tensioning data recording is also available for each drum roll out.

With a max pulling force of 40kN, either capstan can be operated separately with up to 20kN tension. The capstans and motorised reel stands are driven by a silenced 46kW diesel engine. Radiated engine noise is reduced by up to 90 percent at its 1800 rpm operational speed. Each motorised drum is synchronised to the opposing capstan and has a drum weight capacity of 2500kg with a drum diameter up to 2000mm.

“The radio-controlled mast incorporates two independently adjustable guide roller assemblies, providing a maximum height of up to 8 metres and a 20-degree tilt left and right from vertical,” Black continues. “Another unique feature incorporated in the motorised drum stands is the hydraulic width adjustment of the vertical upstands, allowing rapid drum installation and replacement.”

While there is no technical requirement to have an operator in either RRV cab, Work Safe preferences may desire, in addition to the operator in the central cabin, a second person in one of the RRV cabs. To provide maximum versatility, both tensioner modules are mounted on 20-foot ISO container twist lock centers. This would permit the tensioner to be wagon mounted should the need arise. In addition, the two RRV’s can operate on either standard or broad gauge.

Manco Rail currently offers the consist for either short- or long-term hire with both competent operators and full engineering support available.

Productive overhead wire recovery now a reality

Manco Rail believes the traditional way of dropping obsolete or faulty overhead catenary/contact wire and then having the labour-intensive task of cutting it into short lengths for manual handling, will shortly be a thing of the past.

Following informal discussions with OHW senior linesmen, Manco Rail design engineers elected to set about presenting some engineering concepts aimed at significantly reducing the labour content and introduce a high degree of automation.

Within the ultimate design mandate, Manco engineers elected to incorporate other possible tasks that such a unit could accomplish, to maximise utilisation.

The end result was the Manco OHRF (Overhead Recovery and Feed), a multifunction short wheel base unit, based on a vehicle having a GVM of between 12,000kg to 14,000kg.

“Featuring two dual directional and independent motorised drum carriers, the Manco OHRF can recover both catenary and contact wire or twin contact wire simultaneously,” Black says. “Alternatively, the unit can be used to roll out new wire while recovering the obsolete wire.” With a wire recovery capability of up to 6 km/h, Manco Rail says the productivity gains over previous methods have been described as “nothing short of incredible”.

While a significant workforce of up to 12 can typically take close to 12 hours to drop, cut and place wire in bins for collection, the Manco OHRF – excluding the time for dropping wire – can recover a drum in as little as 30 to 40 minutes.

“The best methodology is to recover the dropped wire by progressing down track collecting the laid wire from its dropped position,” Black explains.

“All controls are radio remote operated including the hydraulically adjustable guidance mast that incorporates vertical extension and 20 degree left and right offset from centre. The fairlead rollers are hydraulically powered to assist in maximising cable laying during recovery operations.”

The first full operational tests where carried in December of 2018 at the Melbourne level crossing project where 46 drums of contact and catenary wire was recovered during this short period, representing a significant cost and time reduction over previous methods.

The base RRV incorporates dual front rail wheel hydrostatic drive, failsafe brakes on all wheels and is manufactured in accordance with AS7502, the new RRV standard introduced in July 2016.

Designed for quick on tracking at road crossings, the unit is available in multigauge configuration for both short- or longterm hire.

Contact: rblack@mancoeng.com.au, bryan@manco.co.nz