Signal System

Project Overview

The system on the Yellow Line Monorail Project, Lat Phrao-Samrong connects the Blue Line Ratchada Lat Phrao section in the North to Samrong Station in theSouth. The total length of the line is approximately 30.4 km with 23 elevated stations. The line will be served by one combined depot and stabling area, and one Park & Ride building. The depot has 7 maintenance lanes, 1 automatic washing track, and 1 test track. There is one Central Control Room (CCR) in the Operations Control Centre (OCC) building in the Depot area and one backup Central Control Room (BCCR) in the maintenance workshop building.

Project Characteristics

Approximately 30.4km mainline length at initial stage
23 elevated stations at initial stage
30 trains (4-car per train) at initial stage
1 central control room
1 backup control facility
3 local control (2 for main line and 1 for depot)
1 depot and maintenance area
1 depot and maintenance area
1 training room

Operation Features

Initially, the system will operate with a 4-car train configuration; in the future the system will operate with a 6 or 7-car train configuration depending on the number of passengers..
Platform lengths will be able to accommodate a 7-car train.
The maximum operation speed is 80km/h.
The signalling design headway is 90 seconds and the minimum operation headway is 120 seconds
The average speed for a round trip is 35 km/h
Unattended Train Operation (UTO) is normal operation mode
Manual with Automatic Train Protection (MATP) mode is also available in case there is a need for the train to be driven manually
Non-Restricted Mode (NRM) is provided for use in recovery operation.
Main Technical Features
The Yellow Line Monorail Project employs Alstom’s CityfloTM 650 signalling. Unlike traditional fixed block systems, Cityflo TM 650 is a moving block, communications-base train control (CBTC) system. The occupancyof the train moves along with the train in a continuous fashion and the train control information is transmitted between the train and wayside computers through a wireless radio. The occupancy is generated by the train and sent back to the wayside control system, based upon the worst-case braking of the train.
A full set of CBTC subsystems for the Yellow Line MonorailProject includes: Automatic Train Supervision subsystem (ATS), Automatic TrainProtection subsystem (ATP), Automatic Train Operation subsystem (ATO), Object Controller Subsystem (OCS) and data communication system (DCS).

Main Technical Features

The Yellow Line Monorail Project employs Alstom’s CityfloTM 650 signalling. Unlike traditional fixed block systems, Cityflo TM 650 is a moving block, communications-base train control (CBTC) system. The occupancyof the train moves along with the train in a continuous fashion and the train control information is transmitted between the train and wayside computers through a wireless radio. The occupancy is generated by the train and sent back to the wayside control system, based upon the worst-case braking of the train.
A full set of CBTC subsystems for the Yellow Line MonorailProject includes: Automatic Train Supervision subsystem (ATS), Automatic TrainProtection subsystem (ATP), Automatic Train Operation subsystem (ATO), Object Controller Subsystem (OCS) and data communication system (DCS).

CityfloTM 650 signalling system - features and advantages

Increases safety, shortens headways andimprovesoperation efficiency
Supports full range of automation levels in accordance with IEC 62290-1, for Grade of Automation Level 4 (GoA 4), or Unattended Train Operation, the highest level of automatic train operation mode.
Uses advanced control, computer, redundancy, network and communication technology, conforming to latest industry developments
Wireless communications, which uses the wireless standard IEEE 802.11, 5.8GHz frequency band and an LoS antenna, ensure continuous and reliable train to wayside communication, which effectively solve route defects and interference..
Advanced safety design andsubsystems conform to safety integrity level (SIL)requirements and the ATP and interlocking systems reach theSIL4 safety certification standard.
The ATP and interlocking systems uses 2x2-out-of-2 redundancy structures; ATS subsystems and ATO subsystems use double-machine hot-standby redundancy structures, to improve system availability.
Several stations are grouped into one control area (region) which reduces the separation equipment configuration, repair time and equipment maintenance costs
Multipledriving modes can be adapted to requirements from unmanned automatic driving to manned.
Pre-acceleration and deceleration functions enable train energy-saving operation and improve the passenger comfort.
Advanced stopping accuracy is aligned to theplatform screen door/safety door system
Data transmission subsystem with hot-standby redundancy has an automatic restoration function that prevents single point failure

Signalling System Structure

Overall Structure

To fulfil highly dense and uninterrupted operational features for the Yellow Line Monorail Project, the signalling system provided in this plan is ahighly efficient system with strong availability, reliability, safety and maintainability. Following the area control principle, the signalling system of the Yellow Line Monorail separates into 3 regions: 2 for Mainline and 1 for Depot

Each regional station is equipped with local control which can serve as 2nd level of backup control where both central control room and backup control facility is inoperable.

Overview System Architecture

Project Overview

The Monorail system on the Yellow Line Monorail Project, Lat Phrao – Samrong Section start at Initial Blue Line Ratchada Lat Phrao section in the North and heading South until Area Samrong Station. The total length of the line is approximately 30.4 km with 23 elevated stations. The line will be served by one combined depot and stabling area, and one Park & Ride building. The depot has 7 maintenance lanes, 1 automatic washing track, and 1 test track allowing UTO. There is one Central Control Room in the OCC building in the Depot area and one backup CCR in the maintenance workshop building.

Project Characteristics

Approximately 30.4km mainline length at initial stage.
23 elevated stations at initial stage.
30 trains (4-car per train) at initial stage.
1 central control room
1 backup control facility
3 local control (2 for mainline and 1 for depot)
1 depot and maintenance area.
1 test track
1 training room

Operation Features

At the initial stage, the system will operate with a 4-car train configuration. However, in the future the system will operate with a 6 or 7-car train configuration depending on the number of potential passengers in the future.
Platform lengths will be able to accommodate a 7-car train.
The maximum operation speed is 80km/h.
The Signalling design headway is 90 secs and the minimum Operation headway is 120 secs.
The average speed for a round trip is 35 km/h.
UTO (Unattended Train Operation) is normal operation mode.
MATP (Manual with Automatic Train Protection) mode is also available in case there is a need for the train to be driven manually under ATP supervision by Train Attendant or Station Supervisor as required
NRM (Non-Restricted Mode) is provided for use in recovery operation

Main Technical Features

The Signalling of Yellow Line Monorail Project employs Bombardier Transportation’s latest generation of Signalling called CITYFLO 650. Unlike traditional fixed block systems, CITYFLO 650 requires neither standard track circuits nor an on-board operator. Train-toWayside communication is not done through fixed track circuits, but through a "wireless" communication medium capable of bi-directional transmission.

This system is based on “Moving Block” (MB), “Communications Based” Train Control System (CBTC). By “moving block” it is meant that the “occupancy” of the train moves along with the train in a continuous fashion. By “communications based” it is meant that train control information is transmitted between the train and Wayside computers through a wireless radio. The train occupancy is generated by the train and sent back to the wayside control system. This train generated occupancy is based upon the worst-case braking of the train.

A full set of communication-based moving block train control systems (CBTC) for the Yellow Line Monorail Project includes following subsystems: Automatic Train Supervision subsystem (ATS), Automatic Train Protection subsystem (ATP), Automatic Train Operation subsystem (ATO), Object Controller Subsystem (OCS) and data communication system (DCS).

CITYFLO650 Signalling system - features and advantages

With the CBTC moving block train control system, it can guarantee safety, shorten headway and improve operation efficiency.
It supports the full range of ATP and ATO automation levels in accordance with IEC 62290-1, which is classified as GoA 4 (Unattended Train Operation), the highest level of automatic train operation mode.
It uses advanced control technology, computer technology, redundancy technology, networktechnology and communication technology, which conforms to development direction of rail transit.
The CBTC system uses wireless communications, which uses the wireless standard IEEE 802.11, 5.8GHz frequency band; transmission media is LoS antenna, which together can effectively solve route defects and interference, thus realising continuous, stable and reliable train to Wayside communication transmissions.
It has advanced safety design features, which can eliminate or minimise human error. The safety involved subsystems conform to a safety integrity level requirement; and the ATP and interlocking systems reach a SIL4 safety certification standard.
Its advanced reliable design; ATP and interlocking systems uses 2x2-out-of-2 redundancy structures; ATS subsystems and ATO subsystems use double-machine hot-standby redundancy structures, which can improve the system availability.
It uses an area control method to reduce the separation equipment configuration and reduces repair time as well as equipment maintenance costs within the service life of the whole system. Instead of providing RATC equipment at every station, regional concept is used to group several stations as onecontrol area (region) It has multiple driving modes, which can be adapted to multiple requirements from unmanned automatic driving modes to manned driving modes.
The ATO subsystem uses smooth coordinated control technology and has pre-acceleration and deceleration functions and can realise train energy-saving operation and improve the driving comfort for passengers.
It has advanced train station stopping accuracy, which is suitable for project operation requirements for the platform screen door/safety door system.
The data transmission subsystem with hot-standby redundancy, has an automatic restoration function that prevents single point failure so that it will not generate an effect on the running system.
For all the key subsystems, they use multiple redundancy fault-tolerant designs; in case of a fault, it supports a quick restoration.

Signalling System Structure
Overall Structure

To fulfil highly dense and uninterrupted operational features for the Yellow Line Monorail Project, the Signalling system provided in this plan is safe, complete, advanced, highly efficient system with sound functions, strong availability, high reliability and maintainability. Following area control principle, the Signalling system of Yellow Line Monorail separates into 3 regions: 2 for Mainline and 1 for Depot

Each regional station is equipped with local control which can serve as 2nd level of backup control where both central control room and backup control facility is inoperable.