- Posted 3 years ago

Signalling Installation Design - Part 1

In general, least importance are given to Installation Design compared to System Design ! This is mainly due to lack of awareness and knowledge  among  the key personals within an organisation. An error in a system application software or any design engineering document can be rectified by spending few hours and the cost impact is minimal compared to an error in an Installation Design. As a person who worked in both aspect of these two designs, I felt that we should emphasize more on Installation Design. A minor error in a mechanical cable frame, cable junction box, fixing brackets or a signal mast design will have a huge impact on material wastage, impact of schedule and budget in a larger way. There are various things to be considered to produce an error free design, which I describe based on design and site experience I received in the projects I have executed. I have tried to explain in this article the flow of work that happens in Installation design engineering from the Tender to the execution of installation activities at site. I have divided the work done by installation engineer into the following section. It is defined as per the schedule/flow of activities. TENDER: Firstly, before starting any Installation engineering activities we do have a tender phase. In this phase we analyse basically 2 main information which is important for the project management team to decide the cost. Ultimately everything comes down to the cost, each system has forecasted!!! The 2 main information required during the tender phase is the number of hours we will spend and the number of items we will be procuring. This information is collected in the format of BOQ (Bill of quantity and workload file. So, in this section I will explain what should not be missed (inputs and outputs) during the tender phase: Inputs/Reference documents Requirement matrix: This document has the information from the customer required for each system. Installation engineering team has to extract the installation requirements with respect to each other engineering sub system. This drawing also will have the standards(EN, IS, ASTM, IEC, etc) that should be followed in the respective country. Civil Architecture drawings/CSD(Combined Services drawing): These are a set of drawing which will give an outline of the building and the location of the equipment room in the station or control centre. This will also have the general information on the cable routing inside the building. This drawing will help us to calculate the cable length that has to be considered for each run of the cable. Cross Section drawing of the track: This will give a general information on the type of accessories and mounting support we need to consider for each equipment defined in the scheme plan. This will also provide the information on the cable ducts that can be used for SIG and COM. With this drawing, we also get to know what strategy that can be applied to cross the cables between the tracks. Track Alignment drawing: This drawing will give us the gradient of the tracks and the vertical/horizontal alignment of both the up & down track. This drawing along with scheme plan will help us to calculate the cable length along the track along. Also, this drawing will help us to analyse if the track is elevated, on ground and underground which will in turn help the team to analyse the mounting arrangement for trackside equipment. Scheme plan: This is the deliverable from engineering team that defines the kilometric point of each equipment and the number of trackside equipment. It is used to calculate the cable length and quantify the number of mounting arrangements that needs to be considered against each signalling and telecom equipment along the track. System BOQ: This document will have the information on the quantity of the equipment that will be installed along the trackside and in the stations. We can decide on quantity of the support required for each different equipment. Cable layout: This drawing gives a general information on the cabling schematics between the cubicle in the equipment room and trackside equipment. We use this deliverable to define the type of cables and the length required for each type of equipment. Interface management: This is plan created along with the customer on who will give what information. This also states what are the supports other subsystem require from installation team. Planning schedule: This will provide a general information on the schedule of each activity during the execution of project. This will in turn help the team to forecast the installation engineering activities. Output/ Installation Deliverables Installation BOQ: After analysing the inputs from the customer and other engineering team within the project team (inputs are listed above), Installation team will prepare the installation BOQ. This document contains all the items related to installation such as cable trays and it accessories, mounting support and its accessories, cables, material needed for cable crossing the track, cable tags, tags, racks, base frames, conduits, trackside junction box and its accessories, clamps, cable glands, grounding mechanism, etc. Installation workload file: This document consists of the number of deliverables that needs to be considered along with the hours dedicated to each deliverable. This document will also include the information on the scope of work for installation design team with respect to the site activities (Whether shared or full-time resources is dedicated for each activity). We also include the information on the assumptions taken during the workload calculation. According to the planning of the schedule for each activity we forecast the hours.   For Preliminary installation Design to Detailed Installation Design do follow the page for more....