That’s an observation based on my twenty five years of experience surveying for railway designers.
There can be very few who haven’t heard of BIM but are you aware that BIM Level 2 has been mandated by the government for all public sector projects regardless of size from 2016 onwards?
As you know, BIM is an acronym for Building Information Management. The ‘B’ is an unfortunate part of the acronym that we have inherited from the US, where there it reflects the origins of the system.
However BIM is not just for buildings. BIM will be applied as well to structures, roads, airports, railways, ports and, in fact, anything that is constructed and part of the built environment.
Some say AIM – Asset Information Management would be a better acronym. This is wider-reaching, it is true, but presupposes that the asset already exists whereas BIM starts in the conceptual stage before the asset exists.
For a better interpretation we should consider the ‘B’ as being the verb ‘to build’ then it at least includes the conceptual and design stages through to construction supporting the Grip1 to Grip8 stages.
What is so different about BIM is that it is a total environment of information management that will live beyond Grip8 and throughout the rest of the life of the asset. BIM is a set of protocols and procedures for data exchange by which all information required to develop, operate and manage an asset will be available to everyone at the appropriate stages in the life cycle of the asset.
BIM will satisfy every discipline and will be used by the asset’s developers, planners, architects, engineers, contractors, outfitters, maintainers and operators.
Put simply it is better information management enabling everybody who may be involved in the planning, designing, constructing, fitting out, operating, maintaining, refurbishing and eventually the demolition of an asset to be able to work together efficiently and in harmony.
BIM is the enabler of collaboration
In short – everyone will sing from the same hymn sheet and there will be no conflicts of design, no misunderstandings, no duplication of effort and most importantly there will be no disputes and, as a consequence, there will be no need for dispute resolution.
That’s the theory. Putting that theory into practice will require that every BIM will need to be tailored around and focused on the needs of the target asset’s owner. Therefore, every BIM will inevitably be different but they will all have one thing in common.
The foundation for every BIM is a 3D model of the asset that features every component, fixture and fitting that collectively makes up the asset. Behind the 3D model, and possibly accessed through it by hyperlinking, will be a series of relational databases that contain everything of relevance concerning the asset, its fixtures and fittings. Some BIM’s will be 12D or more.
It follows therefore that to remain relevant the BIM must be continually updated as the project itself develops and matures from ‘concept’ to ‘design’ to ‘as- built’ to ‘as maintained’ to ‘as refurbished’ and finally to ‘as demolished’.
Apart from the owner the surveyor has the only role that will contribute to the BIM throughout the life cycle of the asset.
The roles of the planners, architects, engineers, builders and asset managers will all contribute at different times in the project life cycle but they are all transient in comparison to the role of the surveyor that is central to maintaining the BIM database.
Clearly the geospatial engineers have a huge part to play but don’t make the mistake of thinking it doesn’t affect the commercial managers – it does.
From the moment of design the BIM will start to be populated with programme and phasing of the works right down to the fitting out and the BoQ’s (Bill of Quantities) of the components that comprise the asset. Progress will be mapped against the BIM and monthly measures will drop out automatically.
Throughout the life cycle of the BIM it will be the roles of the geospatial engineers and the commercial managers that will keep the BIM model and its underpinning schedules up-to-date and relevant.
The BIM will be tested continuously during the asset’s life cycle. It will be tested in the areas of accuracy, completeness and currency and if it is found to be wanting at any time there is the inevitability that it will fall into disrepute and it will fail, with the possibility that the ultimate test might be a legal test in the courts.
The culture in rail will not support BIM and must change
Sadly the development of the railways over the best part of two hundred years has been to segmentalise railway operations and maintenance into various disciplines each with its own distinct methods of recording and unique data requirements for decision making.
Often collected at different times, using different methods with a different accuracy requirement and a different focus, these datasets will rarely fit together and are a reason for much of the re-design and re-working that is commonplace in the railway environment.
Permanent Way, OLE, signalling, structures, stations and gauging are just a few of the disciplines that come to mind and which all work their way through the GRIP design stages with different data requirements and with datasets that are not interoperable.
The practice of designing by discrete segment activity results in datasets being commissioned by managers who understand only the dataset they require.
This may indeed provide a ‘fit for purpose’ dataset but it is a dataset that is ‘fit for only one purpose’. Often these datasets will be discarded when the project moves into the next GRIP stage as being not sufficiently detailed or not accurate enough for that next stage. Often, they stem from nineteenth century practices.
You would not be surprised to know that we still get asked if we can do Hallade Surveys! ‘Can we provide Hallade data?’ would be a better question to ask if the designer really wants to work with this type of dataset. The answer would be ‘Of course we can’ but it will be derived from a data set captured by modern methods that are much more accurate and much less resource hungry than a length of string and an offset rule.
Adhering to nineteenth century practices is only one reason why datasets may still be discarded between GRIP stages. Other reasons may be that the data set lacks any traceability in its quality, including accuracy and content.
Two hundred years ago the collection and plotting of survey data was an extremely labour intensive operation and there was clearly a sound commercial reason for limiting the amount collected to that which was ‘fit for purpose’ for only that design stage.
Fit for purpose is a phrase that is still frequently used in the railway industry to justify not spending more than is absolutely necessary to meet a particular discipline’s requirements at different stages of the design. Fit for purpose describes a devalued dataset that has only limited application and does not fit the BIM concept.
The phrase ‘Fit for purpose’ no longer has any currency in a BIM world
…..that has as its foundation a 3D dataset that is available to all disciplines at any time in the life cycle of the asset.
Given that the lifetime of the asset may well be fifty or one hundred years plus, then nobody can foresee the questions that might be asked of the database or foresee for what purpose the data need be fit. The database must at all times be maintained current, complete to an agreed scope and as accurate as the specification (standard) of the day requires.
Fortunately surveying is now a highly automated data collection process that allows comprehensive and highly accurate datasets to be collected at a much earlier stage in the project.
GNSS (the generic name for all satellite navigation systems including GPS), digital aerial imagery and LIDAR, automated robotic total stations and 3D scanning have all made data collection cheaper, more accurate and more comprehensive than ever before. Surveyors now routinely collect data with an accuracy level of just a few millimetres and for little or no additional cost. These rich data sets can be mined for additional data as the project lifecycle progresses and the need is recognised.
The cost of producing high accuracy survey datasets from this data has shifted from the field data collection into the office with the processing, data abstraction and CAD modelling. The 3D point cloud, the product of the LIDAR and 3D scanners when registered to grid and datum, will likely become the source dataset underpinning the future BIM.
Other bespoke datasets needed for design, operation or maintenance such as CAD models, clearance files, heights and staggers to name just a few will all be derived from this source dataset.These derived datasets will only be produced by the surveyors at the time when they are needed thus minimising any unnecessary costs.
It may well be that parts of the source dataset will lay archived and untouched until a question is asked, possibly at a future stage of the asset’s refurbishment. ‘Do we have space for a new CMS in the void?’ and ‘What steelwork is there in this concrete?’ might be typical questions where the answers are readily available from the source dataset.
The government’s BIM Task Group recognises the central role that surveyors will play in keeping the BIM relevant and has agreed the formation of a new group to formalise the role of the surveyor in the BIM environment.
The new group, called Survey4BIM, has been formed under the auspices of the government BIM Task Group and this is under the direction of and being chaired by the senior vice president of the Chartered Institution of Civil Engineering Surveyors, Ian Bush.
This group will be producing the procedural and guidance notes that will cover the correct formation and maintenance of future BIM’s.
What is needed for a culture change in rail?
The benefits of BIM are clearly understood by government and the challenge for the railway industry is to bring those benefits to the ‘coalface’.
The fundamental concept of BIM is for better information management and one hymn sheet for all disciplines. From this hymn sheet it will be the job of the surveyors to derive the unique datasets, heights and staggers or gauging for instance, that the individual disciplines require.
‘Fit for purpose’ should be replaced in the railway vocabulary with ‘Fit for BIM’. Individual disciplines are too inwardly focused to be able to conceive a functional all-embracing BIM although they will need to buy into it and contribute to it. The ownership of the BIM therefore must rest with the asset owner and not with any one discipline or, indeed, any one project.
It follows that the asset owner must assume responsibility for the design, integrity, maintenance and currency of the BIM. Whether this is done in-house or by buying in the resources will be a commercial decision for the railway industry.
At the very least the design and maintenance of the BIM must be taken out of the project level and must be seen as a regional or national asset with a dedicated management resource. A common BIM database framework needs to be developed and rolled out on a regional or route basis to encourage local ownership, interest and enthusiasm. Project managers need to be trained to ‘think BIM’ and leverage the availability of information.
Can it work? Yes it can
The rail industry already has well- respected and very comprehensive national standards for data collection and surveying. These surveying standards cover the procedures, scope content and accuracy levels that are required to satisfy the complete range of design and compliance requirements. They are also simple to aggregate and harmonise into one standard of data set that will satisfy all current design requirements.
Survey once and use many times is the essence of BIM but this aspiration will only be realised if the dataset has the content and accuracy to support the design decisions. I have no doubt that there are other major projects that have datasets approaching BIM level content but from my own experience I would hold up the Thameslink project as being one that approaches best practice.
Having been connected with the programme since its inception, my company has helped the project grow its data base from ‘survey for design’ through the design and construction stages and more recently through the ‘as built survey’ stage.
Throughout the project the data set has been maintained at an accuracy and content to satisfy all aspects of the design and the Thameslink team have made it available to all consultants, design teams and contractors through ProjectWise.
Because of the foresight of the Thameslink team there now exists a highly detailed ‘as-built’ dataset that is the perfect foundation for the BIM that will take the scheme many decades into the future.
Of course there are lessons to be learnt and there is always room for improvement, but the concept of longer- term thinking and making a conscious investment in BIM is the only way to efficiency and cost saving over the lifetime of the asset.
And that’s why the culture in rail must change…