Crossing the river – and how!

30/05/2017
This one of those stories which we wonder should we post or not as it is hardly strictly process automation or test & measurement. We have decided to include it because it is technologically interesting as well as an innovative application.

Since 19 November urban mobility in the Breton city of Brest (F) has been boosted by two cable cars carrying up to 60 people who travel more than 400 meters above the River Penfeld, with a power consumption that is potentially close to zero. Supported by Leroy-Somer (now part of Nidec Corporation) , the companies Bartholet France and Seirel are behind this achievement which is a world first in terms of technology.

Brest Métropole wants to refocus the city over the banks of the River Penfeld. The cable car system is aimed at strengthening the trade links between both sides of the river. With a range of 420 meters it links the city center with the new Capucins district, which has been built on 16 hectares of former military grounds. The structure designed in accordance with original and innovative technology where the two lines cross over each other via a “flyover” system is a first internationally. The two cable cars cross over each other instead of passing each other at the same level as traditional cable cars do, and they then arrive at the same platform. The scale of the system and the stations, including the ground required, are reduced as a result, thereby also resulting in a reduction in overall civil engineering costs. This is a particular benefit in an urban environment where space is limited. This innovative approach enabled preservation of the Capucins station building, which is protected as a national historical monument. As such the cable cars cross one single steel pylon which integrates into the surrounding environment of dockyards and their cranes. Each car is attached to two carrying cables 50mm in diameter stretched to 88 tones. The counterweight effect generally observed on mountain installations is avoided as the cable cars move simultaneously over most of the route.

Low power consumption
One of the challenges posed by Brest Métropole involved implementing a solution with low power consumption. The idea was therefore to recover the braking energy, but the energy operators have not yet systematically developed the full potential for reinjection of current into their network. The legislative framework provides for this, for solar energy production for instance, but certainly does not do this when the system consumes and reinjects current over very short cycles, as is the case in Brest. The solution therefore consisted in storing energy in super capacity batteries when the cable cars are descending, in order to then reuse this energy for the subsequent ascent.

The project was awarded to Bartholet France for the cable car system, and to Seirel, an expert in electrical equipment and safety automation, for the transportation via cable. “We made contact with several suppliers, and only Leroy-Somer had the experience with this type of application, and was also able to provide all of the electromechanical components”, explains Thomas Savin, project manager for Seirel Automatismes.

The IMfinity LC motor from Leroy-Somer drives the traction cables.

The heart of the system, i.e. the drive for the traction cables, is driven by two latest generation Leroy-Somer IMfinity LC 315 asynchronous motors (300kW, 1500rpm, 460V) with liquid cooling, assembled as master-slave on the same shaft. This installation provides the additional option of double redundancy since just one of the two motors is enough to continue operations in degraded mode (low speed). The motors are controlled by two Leroy-Somer Powerdrive MD2S inverters, which are in turn supplied by Powerdrive MD2R active front-end rectifiers connected to the power network. A DC converter, also from the Leroy-Somer range, enables management of the operations for the M65V385F supercapacitors developed by Blue Solutions (Bolloré Group). The supercapacitors have been specially designed to meet the needs of industrial applications requiring high power ratings. Meeting the most demanding functional specifications, they charge and discharge in just a few seconds and provide service lives of several hundred thousand cycles.

“This achievement would not have been possible without Leroy-Somer’s expertise in project engineering”, says Guillaume Bourgoint, marketing applications manager for Leroy-Somer. “Through relying on a huge range of motors and variable speed drives based on different technologies, we are able to offer our clients custom solutions in terms of drive and automation systems. As such, linking the IMfinity LC motor, characterized by silent power, with the Powerdrive MD2 inverter, with custom power, seemed like the obvious solution to us given the specifications and constraints of the application”.

“We appreciated Leroy-Somer sharing its expertise and helping us during the project design phase with its solution-based approach and experience. What’s more, having just one single point of contact responsible for all of the moving components was the perfect guarantee for us in a project as groundbreaking as this one. We specifically wanted one single supplier for the motors and their controls. We have traditionally used a different brand of converter, but configuring the Powerdrive MD2 from Leroy-Somer turned out to be child’s play”, adds Thomas Savin.

In the event of network loss, an emergency mode using an electric generator with a LSA 44.3 low voltage alternator, also manufactured by Leroy-Somer, enables the cable cars to be returned to the stations. Safety has been reviewed right down to the last detail in order to ensure protection against any eventualities.

“This is the first time a cable car system has included an energy recovery solution with batteries. This achievement is a direct reflection of our company, which is able to position itself on more complex engineering projects, and will no doubt be an inspiration for other projects around the globe”, explains Nicolas Chapuis, Managing Director at Bartholet France.

Silent and compact
“Another challenge in the project was that the area available for installing the motors was in the immediate proximity of the passengers. The project’s groundbreaking industrial design meant that the motors are just a few centimeters behind a glass cabinet visible to users. The equipment therefore had to be silent and compact for the purposes of the site ergonomics and for passenger comfort. Once again Leroy-Somer stood out against the competitors in this area too with its IMfinity LC motor solutions”, adds Nicolas Chapuis.

With liquid cooling, the IMfinity LC asynchronous motors are up to 25% more compact than a motor cooled using air with equivalent power. Their sound level is also reduced by 10 to 20 dB, thereby enabling optimum acoustic discretion. This benefit is explained by the efficiency of the cooling circuit which surrounds the motor system entirely. Its dependable design and Premium IE3 energy efficiency make it one of the most accomplished motors in the IMfinity range. “The LC series, available from 150kW to 1.5MW, is ideal for all cases where the motor is close to the operators or users of the application. It meets the increasingly urgent need for acoustic comfort related to working equipment for teams in workshops or for users located nearby”, explains Guillaume Bourgoint.

Significant benefits
The route for this cable car system is particularly suitable for an energy recovery system, as it is implemented initially during ascent and then during descent, with the departure and arrival points both being at an equivalent altitude. Energy is consumed in order to arrive at the line’s summit point. Once this point has been crossed, the descent phase constitutes a source of braking energy that can be reinjected into the system in order to supply the ascent once again, thereby resulting in a very significant reduction in energy costs.

“This achievement could potentially be used as an example for other industrial applications, such as for lifting”, explains Thomas Savin. “The theoretical energy savings amount to more than 90%, but the main obstacle today relates to the supercapacitors. Here we sized them in order to store around half of the energy required, and this itself represents an investment of 200,000 euros. This cost will probably fall rapidly in the near future”.

A porthole provides the braver passengers with a vertical view of the cable car’s route!

@Leroy_Somer #PAuto #France #Transport

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New monitoring network for Scottish ports!

05/07/2015

Historically, ferry masters operating off the west coast of Scotland would have to sail to a port and on arrival visually assess the weather and tide conditions before deciding whether safe berthing alongside the pier or quayside would be possible. This wastes time and fuel, and can causes immense frustration among passengers, who may see ferries come close to a port, but thereafter depart without berthing when conditions are determined by the ferry Master to be unsafe. These ferries provide a critically important lifeline service to the islands, so the reliability of ferry services is extremely important.

MV_Caledonian_Isles

With multiple sites in island locations, remote access to accurate local data providing live information on tide level and key climatic conditions could facilitate substantial improvements to the service by aiding the Masters to make a more informed decision at an earlier stage in the voyage – in some instances even before departing the previous port or harbour. The berthing of ferries is a highly skilled job, particularly during bad weather, and the decision on whether a specific ferry can safely berth at a specific port is subjective and ultimately can only be taken by the ferry Master.

Following a competitive tendering process Caledonian Maritime Assets Limited (CMAL), which owns many of the ferries, ports and harbours in the region, procured a network of 15 tide and weather stations from instrumentation specialist OTT Hydrometry. The new monitoring equipment provides live data on port conditions to enable the ferry sailing decisions to be made in a timely manner.

CMAL Harbour Master David McHardie says: “OTT installed the first monitoring station in August 2014 and the network is now almost complete with sensors providing data every 1 minute via UHF radio to ‘gateways’ in the ferry offices, which then submit the data via the internet to a central server, which can be remotely accessed by authorised users.

“We have a regulatory requirement to monitor the tide level in our statutory harbours, but this system also provides essential weather information for our ports. In the past, these measurements were taken manually, so the availability of continuous multiparameter data is an enormous improvement – not just in the quality and value of the information, but also in the safety benefits for harbour operations staff, that this provides.”

OTT_Monitoring_Station

OTT Monitoring Station

The safety considerations involved with the berthing of ferries relates not just to passengers and crew but also to the pier hands that assist with mooring operations in a wide variety of often extreme weather conditions. “Mooring operations are inherently high risk activities; handling ropes can become extremely heavy when wet and subject to enormous forces when under strain,” David says. “So, it is important for us to be able to assess the impact of wind, temperature and waves to protect harbour operations staff. Severe weather berthing conditions can also potentially cause damage to ferries and the structures within the ports, so again, detailed data on localised conditions can help prevent accidents and support insurance claims when necessary.”

The availability of live data on port conditions therefore enables the ferry Masters to make better informed decisions at an earlier stage, thereby saving time, fuel and costs. It also means that passengers are provided with earlier warnings of potential ferry cancellation.

Emphasising the growing need for data, David says: “In recent years, severe weather events appear to have become more frequent and they seem to develop faster; for example, since the monitoring network was installed, we have recorded a sudden drop in temperature of 8°C in just 5 minutes at the port of Armadale on the Isle of Skye, and a maximum wind gust of 96 knots at Castlebay on the Isle of Barra. These conditions represent a rapid deterioration of conditions and the monitoring network enables us to respond quickly and effectively.”

Each monitor is located adjacent to the main berthing area on the pier with a lockable GRP control box. The system is comprised of: an OTT radar level sensor; a Lüfft ultrasonic weather monitor measuring wind speed, gust and direction, air temperature and barometric pressure; an Adcon radio unit with back-up batteries and a marine grade antenna. The radar tide level sensor is an OTT RLS, a non-contact sensor employing pulse radar technology with a large 35m measurement range. Both the RLS and the weather sensors, which have no moving parts, have extremely low power consumption, which is vitally important for installations at remote sites. At two locations it was not possible to install a radar sensor so an OTT CBS (bubbler sensor) was installed providing comparable levels of accuracy and reliability.

Robin Guy managed the monitoring network project on behalf of OTT Hydrometry. He says: “We were obviously delighted to be awarded this contract; it’s a good example of the bespoke monitoring systems that we are able to develop, integrating our sensor, datalogging and telemetry technologies to meet customers’ specific needs.

“Before awarding the contract to OTT, David visited four of our existing installations at the Greenock Ocean Terminal near Glasgow to check the reliability of our equipment in demanding conditions. However, in addition to the ruggedness of this equipment, it has also been designed to cope with interruptions to the mains power supply. The monitors are therefore battery powered and data is transferred from the monitors to the port office gateway via low power radio.”

Monitors on end of pier!

Monitors on end of pier!

Now that the CMAL monitoring system is installed, David is looking for ways to leverage the value of the data. For example, radio data transmission works very well over water, so it should be possible to fit the same technology on ferries so that the ferry Masters can access the data directly, instead of having to call the port office for a verbal update. The OTT monitoring network also incorporates an email alert system, and whilst this has not yet been configured, it will be possible in the future for ferry masters to receive email alerts warning them when pre-specified port conditions arise. “We would also like to eventually make the data available to the public as part of an enhanced harbours information system,” David says. “However, when a ferry has berthed, with the monitoring system being located on the pier, the vessel can cause a wind shadow; which means the wind data during that period can be potentially misleading. It has to be remembered that this system remains only an aid to navigation.”

Summarising, Robin Guy says: “This system demonstrates the value of remote monitoring data, but also highlights the importance of low power, rugged, reliable instruments in harsh environments. The modularity of the system is also very important because it enables us to deploy the most appropriate instruments in each individual location.”