What we cover.
Most rail structures in use were designed under codes that no longer exist, to loading that has since changed, and have spent decades accumulating condition. Assessment establishes present capacity against present loading, and it is only as good as the condition information behind it. Where capacity falls short the useful output is not a failure notice but a set of options: revised loading, monitoring, management, or strengthening priced against each other.
- Capacity assessment of underbridges and overbridges
- Footbridge assessment including crowd and vandal loading
- Masonry arch assessment
- Metallic and composite deck assessment
- Retaining wall and lineside structure assessment
- Condition survey feeding directly into the assessment
- Strengthening options appraised and compared
- Reporting written for the asset owner's acceptance process
What rail bridge and structure assessment actually involves.
Assessment is condition-led. A capacity figure derived from original drawings and no inspection is a design check, not an assessment, and it will be treated as such. We take the condition of the actual structure as the starting point: section loss, defect distribution, bearing condition, drainage and the things that have been done to it since it was built.
Where the assessment does not pass at the first level we work up through the assessment levels rather than jumping straight to strengthening, because the cheapest structural intervention is usually the one a more refined analysis makes unnecessary.
We start from the condition of the actual structure rather than from the original drawings, and where an assessment does not pass at the first level we work up through the assessment levels before recommending strengthening. The cheapest structural intervention is usually the one a more refined analysis makes unnecessary.
What does a rail bridge assessment establish?
What the structure can safely carry in its present condition, against the loading the asset owner specifies, to the standards that apply to that asset. It starts from a condition survey rather than from the original drawings, because section loss and defects change the answer. Where capacity is short, the assessment sets out the options: refined analysis, revised loading, monitoring, management or strengthening, with the engineering case for each rather than a single recommendation.
- Assessment led by condition, not by original drawings
- Worked up through assessment levels before recommending strengthening
- Designs checked and signed by a Chartered Structural Engineer
- Reporting written for the asset owner's acceptance route
- Professional indemnity insured
The codes behind rail bridge and structure assessment.
BS EN 1990 through BS EN 1999 govern the basis of design, actions, and the design of concrete, steel, timber, masonry and aluminium structures. Every calculation we issue references the relevant Eurocode part and its UK National Annex, and states which parts were applied.
Structural analysis and design in Tekla Tedds and Tekla Structural Designer, with Autodesk Robot, CSC Fastrak, CSC Portal Frame, MasterSeries and Hilti Profis used where a scheme suits them. Drawing production in AutoCAD, and modelling in Autodesk Revit where a project is delivered in BIM. Output is issued as readable calculations rather than raw software printouts, so a checker or a building control officer can follow the reasoning.
The Building Regulations requirement your local authority Building Control checks against. Our calculations and drawings are prepared to demonstrate compliance so your submission is accepted without back-and-forth.
Every report and calculation package is backed by professional indemnity cover, which is what lets a lender, Building Control or another engineer rely on it.
From enquiry to sign-off.
Enquiry
Send drawings or describe the problem. We confirm the scope, the deliverables and a target timescale.
Information
We agree the survey, drawings or data we need and any site access required.
Engineering
Design, calculation or assessment to the relevant Eurocodes and UK National Annex.
Issue
A clear, defensible report or set of calculations, with assumptions and limitations stated.
Real structures, surveyed and engineered.
Common questions
What is the difference between assessment and design?
Design establishes what a new structure needs to be in order to carry a given load. Assessment establishes what an existing structure can carry in the condition it is in now. The codes are different, the partial factors are different, and assessment allows refinement that design does not, because the structure already exists and can be measured rather than assumed.
Do you need a condition survey before assessing?
Effectively yes. An assessment run from original drawings alone assumes the structure is as-built and undamaged, which after several decades it will not be. Section loss, defective bearings, drainage failure and previous alterations all change capacity, and an assessment that has not looked at them is not defensible.
What happens if the structure does not pass?
Not passing at the first level of assessment is common and is not the end of the process. The usual sequence is to refine the analysis, then consider whether the assessed loading can be revised, then whether the structure can be managed or monitored, and only then whether it needs strengthening. Going straight to strengthening spends money that a more careful assessment often removes the need for.
Can you assess masonry arches?
Yes. Masonry arch assessment behaves differently from framed structures and rewards a condition-led approach, because arch capacity is sensitive to ring separation, spandrel condition, fill and drainage in ways that a drawing will not show you.
Related services and resources.
03Structural Inspection Reports
04Structural Design & CalculationsCalcs, building regs, extensions, foundations
05Surveys & ReportsPre-purchase, inspection, due diligence
06Conservation & HeritageListed buildings, historic repairsTell us what you are building.
Send the drawings or describe the project. We confirm scope, deliverables and a realistic timescale.
Start a project