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Irrigating the Dijon tramway

 

We visited the tramway site in Dijon on a cold January day when it was covered with snow. In view of the length of the track, the work has been divided up into 3 lots. The work involved in each lot includes laying out the lines, platform, green spaces, raw water supply and irrigation system. The company JFL Concept is the project manager for the integrated automatic irrigation system.  We accompanied Mr. Poissonnet from the company JFL Concept during his site visit.

TThe route of the tram system, which is Y-shaped, consists of three branch lines that join up at the city centre, at the place de la République. We went to the place DARCY, just a stone's throw from the place de la République, where we were shown the water source that will allow the green areas of the system to be irrigated. A majestic gate leads on to a beautiful park with hundred-year-old trees. "Further along in the gardens, under the vaults, there is a water reserve, which will supply the raw water system, and then the irrigation system", explained Mr. Poissonnet. This water is pumped up from the water table via a pump at a parking lot under the gardens. It can be directly used for irrigating the lawns, without any pre-treatment required.  A water storage facility with a capacity of 2,000 m3 is in the process of being renovated. «The raw water connection is located in front of the garden », continued Mr. Poissonnet. The company Lyonnaise des eaux, which is responsible for the raw water supply, carried out a survey during the hot season, informing that: the pumped water should be sufficient to irrigate the tramway’s 16 km of grassed area.

 

We then travelled to the place de la République, to the centre point of the «Y», where the three branch lines meet. « There is no grassed track in the city centre. In the place DARCY, the potted trees are watered with bubblers. A small 3 m3 branch connection will allow the trees to be irrigated », explained Mr. Poissonnet. Furthermore, a fountain is due to be built at the place de la République. JFL CONCEPT will be involved as the expert adviser for checking both the equipment and the installation.

 

The irrigation system of the tyramway

 

You have to travel away from the town centre to catch a glimpse of the first sprinklers. The grassed track area stretches for 16 km along the whole length of the tram platform (for the sake of economy, the approaches will not be irrigated). « The irrigation  system will be installed in several stages, somewhat like a game of Lego, where all the different pieces must be put in place one after the other, in the proper sequence », explained Mr. Poissonnet.  The pipes and the electric wires of the solenoid valve controls will be buried at a certain depth (primary network, which is now almost completed). After this, the contractors responsible for constructing the tramway will lay the rails.  Once the rails are in place, the irrigation teams will return to the site to put the smaller pipes in place, these making up the secondary network for supplying the sprinklers. The primary network is 90% completed and the secondary network should be finished in late summer.

 

At this stage of the project, the teams are in the process of installing the secondary network.  The tramway project is divided up into three branches, and three different companies manage each of these branches:

 

  • The company Tarvel is managing the southern branch line, which leads to the town of Chenôve at its terminus.

 

  • The northern branch, managed by the company VDS paysage, will lead to an industrial estate that is being built at the end of the line.

 

  • The eastern branch, which leads to the universities and the town of Quetigny, is managed by the company ISS Espaces verts.

 

We have met up with each of the site managers of the three teams. The principle is always more or less the same for the three branches, consisting of:

 

One meter chamber, which covers an 800-meter section of the irrigation system.  « This is a chamber measuring 3 x 1.5 metres, which houses the hydraulic equipment, a DN 65 water meter and a DN 80 irrigation water meter, which at the same time acts as a pressure regulator with a master valve », explained Mr. Poissonnet.  On account of certain obstacles (such as the crossing, Station, fast lane,...), a new meter chamber has been installed for the primary network. Lot 1 has three meter chambers and lots 2 and 3 each have four.

 

The platform width is not the same along the whole tramway system. « If the tramlines are more or less in the middle, then there will be grass strips either side and the platform will be quite narrow (6.5 - 7 metres) », explained Mr. Poissonnet. The sprinklers selected for this layout are standard Hunter spray heads with MP Rotator spray streams. The tramway has 4,200 of these in total.  When there is also a strip of grass in the middle, between the two tramlines, then the platform is wider (10 metres) and Hunter 120 sprinklers have been chosen for this; there are 650 of these along the whole tramway system. Finally, with a layout where the two tramlines are separated, the platform is, therefore, narrower, and, of course, the Hunter nozzles are used with the sprinklers: «The sprinklers are always laid out in a square configuration, whereas with the nozzles, the layout is triangular. » Whichever type is used, for reasons of economy, the sprinklers are installed along the edges, and never in the middle of the platform, as can be seen in other tramways. «The irrigating time is longer, but the sprinkler can cover a larger surface area », continued Mr. Poissonnet. In the middle of the platform, at a distance of about every 80 metres, there is a solenoid valve chamber, equipped with ICV Hunter valves, linked to a pressure regulator.

 

Irrigation management is piloted from a computer via a Claber IDS central control system. This system allows for the required amount of water to be distributed exactly, calculated from the weather data supplied. The central control system includes 12 boxes for the IDS satellite units, 247 decoders, including master valve decoder, and a Météolab controller connected to the existing central control network in the city of Dijon.

 

The irrigation system - relevant figures

 

- 4,200 PRO Spray pop-up spray heads

 

- 650 x I20 sprinklers

 

- 235 x 1½" solenoid valves (ICV)

 

- 2 x 1" solenoid valves (ICV)

 

- 60 bubblers

 

- 110 solenoid valve boxes

 

- 12 meter chambers with a capacity of 25 m3/h (3.5 x 1.5 m)

 

- 1 overpressure station with a capacity of 25 m3/h

 

 

The Irrigation Management Central Control System supplied by Espaces Verts for the DIJON Tramway:

 

This is a Central Control System consisting of a Central Processing Unit acquired by the client, loaded with the AQUAMETEO IDS® software from CLABER. This central processing unit has, among others, a communications module aimed at remotely sending and receiving information to and from 12 satellite units installed in the Field. The method chosen by the local government agency controlling this Tramway for communicating between the Central Unit and these Satellites is the fibre optic system, just like the option chosen for the installation of the ANGERS Tramway, which is also equipped with the CLABER system.

 

Each satellite unit controls a determinate number of valves, via an electric cable with branch connections to the decoders (265 decoders in total), with each, in turn, being connected to the Solenoid Valves.

 

The 12 CLABER satellite units had to be specially made so that they could be installed in the satellite boxes chosen by the research department, and thus this equipment could be integrated into the surrounding landscape in the best possible manner.

 

The system has been designed in such a way that it can apply the precise amount of water, on a daily basis, in accordance with certain criteria, and more specifically on the basis of the meteorological data provided automatically by a CLABER weather station, installed on site.

 

In addition to the numerous possibilities offered by the Central Control system installed in Dijon, it will also be possible to have information about the amount of water consumed, via flow meters installed on each site. These meters will enable the system to determine any possible water leaks in the system, send out alarm signals when anomalies are detected and shut down the valves associated with the section where the leaks occur.

 

This hi tec installation has been carried out by the Company SIREV.  This same contractor had already accepted the challenge of meeting the stringent demands of installing the ANGERS tramway, in partnership with CLABER.

The work, which began in October 2010, should be completed by the beginning of 2012.

 

Data sheet

 

Client: Grand DIJON urban authority

 

Main Contractor / General Project manager: Egis Rail

 

Irrigation contractor / Project manager: JFL Concept

 

Subcontractors: Tarvel (Lot 1), VDS Paysage (lot 2), ISS Espaces Verts (lot 3)

 

Length of tramway: 18 km of track, including 16 km. set in grass (grassed tracks)

 

Hunter sprinklers, nozzles and solenoid valves, Claber central control system

 

1 meter chamber with a capacity of 4m3/h

 

48 km of Ø40-63 and Ø90 pipes.

 

18 km of cabling.

 

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