RAD — Railway Alignment Designer Open the designer Open the designer

Reference

The engineering behind the tool, and how to drive it. The full manual is below; the sections after it are the short form.

New to it? The designer opens with a short tour and a guided first alignment on your first visit, and both stay under Help for whenever you want them again: take the tour, or make a first alignment step by step.

The main designer groups commands by task: Data for surveys and reference lines, Alignment for route and profile design, Structures for crossings and bridge workspaces, Stations for station planning and yard workspaces, Review for checks, comparisons and 3D views, and Output for sheets, deliverables and estimates. File, Save, Undo, Redo and command search stay in the header. Opening a group leaves the design unchanged; stage commands still check the prerequisites. The arrow beside the groups collapses the command row to give the drawings more space. Output → Detailed estimate can also open a standalone component bill before the alignment stages are complete.

The manual

Twenty-six chapters and four appendices: what the tool is, how a design is made from two points on a map, what is checked, what comes out, and the limits of what any of it may be asked to claim. Edition 3 · 13 October 2026 adds desktop usage, CAD drafting, project presentations, tender preparation, the activity indicator and precise notations, with application screenshots and explanatory diagrams.

Part I · Orientation

What it is and what it is not · getting started · a tour of the workspace · the four stages and the gate between them.

Part II · The process

Routing a corridor · a line where a line already runs · drawing by hand · the geometry · compliance and repair · crossings and hydrology · bridge workspaces · station yards · component estimates and rate analyses · the workbench · both cab rides · deliverables.

Part III · Reference

Compliance code reference · the six standards side by side · file formats and schedules · architecture · verification · deployment · troubleshooting · limitations.

Appendices

Glossary · where the rates come from · the worked examples · a one-page quick card.

Go straight to detailed estimates, bridge design and GADs, Cab ride 2, or saving and reopening a project. Sign in to read the current manual or use Print / save as PDF. Open the illustrated training module and download its PowerPoint.

Why the curve has a curve at each end

A train entering a circular curve from a straight would meet full centrifugal force instantly. So the two are joined by a transition whose curvature grows steadily from nothing to 1/R. The curve that does this is the clothoid, or Euler spiral:

1/r(l) = l / A²    where A² = R · Ls
θ(l) = l² / (2A²)
x(l) = ∫ cos θ ds    y(l) = ∫ sin θ ds

Cant is raised along that same length, at a constant rate. Because curvature and cant rise together, the resultant force stays in the plane of the track the whole way through. That is the entire reason the clothoid is the right shape.

Fitting one at an intersection needs two derived numbers. The spiral pushes the circular arc away from the tangent by the shift p, and the spiral begins k back from the foot of the perpendicular from the arc centre. Standing the centre off (R+p₁) from one tangent and (R+p₂) from the other and solving gives the tangent lengths:

T₁ = k₁ + [ (R+p₂) − (R+p₁)·cos Δ ] / sin Δ
T₂ = k₂ + [ (R+p₁) − (R+p₂)·cos Δ ] / sin Δ

With equal spirals this reduces to the familiar T = k + (R+p)·tan(Δ/2), and with no spiral at all to R·tan(Δ/2). Asymmetric transitions are not a special case — they fall out of the same expression.

The tangent points are named the usual way: TS tangent to spiral, SC spiral to circular, CS circular to spiral, ST spiral to tangent. Without transitions they become TC and CT.

Cant, deficiency and excess

Equilibrium cant balances the centrifugal force exactly, at one speed:

C = G · V² / (127 · R)    [mm], V in km/h, R in m, G in mm

G is the dynamic gauge — the distance between rail centres. With G = 1750 mm this is the Indian Railways form C = 13.76 V²/R; with 1500 mm the standard-gauge C = 11.81 V²/R. One equation, every gauge.

Real track carries trains at different speeds, and only one cant can be built. The fast train is left short by the cant deficiency, the slow one over-canted by the cant excess. So a cant exists at all only when

C_eq(V) − Cd_max  ≤  C_eq(V_slow) + Ce_max

Rearranged, that sets a minimum radius for mixed traffic which is separate from, and often larger than, the one the fast train alone implies:

R ≥ G (V² − V_slow²) / (127 (Cd_max + Ce_max))

Below it no applied cant satisfies both trains, however you choose it. The tool reports this as R_MIXED, and it is the reason it will sometimes insist on easing a radius rather than adjusting cant.

How long the transition has to be

Three independent criteria; the longest wins.

rate of change of cant      L = C · V / (3.6 · limit)
rate of change of deficiency  L = Cd · V / (3.6 · limit)
cant ramp gradient            L = C · N / 1000   (1 in N)

Each curve card names which one governed, so you can see what to relax if the transition is longer than the site allows.

The compliance codes

Errors break the standard's exceptional limit. Warnings sit between the normal and exceptional limits, or flag desirable practice. Every finding names the rule it comes from, the clause behind it and the ways out, under Why?. Most also have a Fix button; the ones that would need the route, the speed or the works changed are advisory, and say so rather than guessing on your behalf.

The report groups by the part of the design a finding belongs to, and the filter box takes a code, a chainage or a word from the message. Strict reports every warning as an error. The ⊘ button on a finding turns that rule off for the project — recorded in the project file, and listed above the report, because a check that has quietly stopped running is worse than one that fails.

Horizontal

R_MIN, R_ABS radius below the minimum for the speed or the gauge · R_MIXED no cant serves both speeds · CANT_MAX, CD_MAX, CE_MAX cant, deficiency or excess over the limit · ARC_SHORT too little circular arc

Transitions

NO_TRANS cant with no transition to run it in · LS_SHORT shorter than required · DCANT_DT, DCD_DT cant or deficiency changing too fast · CANT_GRAD ramp too steep

Between curves

IP_OVERLAP, OVERLAP curves running into each other · NO_STRAIGHT, STRAIGHT_SHORT too little straight between them · REVERSE_OK a reverse curve whose transitions meet cleanly

Vertical

NO_VCURVE a grade change with no curve · RV_MIN vertical radius too small · AV_MAX vertical acceleration over the limit even where the radius passes · VC_SHORT a vertical curve too short to set out · V_OVERLAP vertical curves colliding

Gradients

GRADE_MAX over the ruling gradient · GRADE_COMP over it once compensated for curve resistance · GRADE_SHORT a gradient too short to run a train over without surging · V_ON_TRANS a vertical curve twisting the track where cant is already changing

Curvature steps

R_RATIO compound curves whose radii are too far apart · VIRT_TRANS a curve entered with no transition, where the deficiency has to build over the vehicle's bogie centres instead of a designed length

Terrain and works

Only when a ground profile is loaded. CUT_DEEP, FILL_HIGH a tunnel or viaduct far past the depth at which it became worth building · STRUCT_ON_TRANS a deck or bore spanning a transition, so it has to be built to a twisting surface · TUNNEL_DRAIN a bore too flat to drain · EARTH_BALANCE cut and fill badly out of balance

The engine itself

RULE_ERROR — a group of checks failed to run. The rest of the report still stands, and this says which part of it is missing rather than going quietly blank.

Laying out a route

Design a route opens on the whole country and takes an ordered chain of points. A and B are the two ends. Everything between them — C, D, E — is obligatory: the router is free within a leg and pinned at every one of them. That is the difference between a corridor a cost function happened to like and one that meets the junction, uses the gap and serves the town, which is what a railway is actually routed on.

Three ways to place a point

Click the map, type a coordinate — 27.175, 78.042 or 27 10 30 N, 78 02 31 E — or search a place, a station name or a station code. Codes are what no geocoder indexes and what every railway person has to hand, so AGC and NDLS are looked up as OpenStreetMap tags directly.

Moving them

Every pin drags. Click the corridor between two pins to add an obligatory point on that leg, or use ＋ Intermediate point and then click. Right-click a pin to remove it. A pin dragged away from the station it was found under loses that name, because it is no longer that station.

What survives

The grid path is thinned into an IP polyline, and thinning is exactly the step that could slide the route past a point you pinned. It does not: where an optional vertex crowds an obligatory one, the optional one goes, and the result names the IPs that were held.

Speeds

Design speed sets the curves; slowest traffic sets cant excess, since cant chosen for 160 km/h is cant a goods train rides on its inner rail. Slow traffic is capped at line speed, because above it, it is not slow traffic.

Your own starting point

A new project opens on Indian Railways broad gauge at 110 km/h unless you say otherwise. Considerations → My defaults → Save these as my defaults keeps the standard, both speeds, the design limits and every considerations tab as the panel holds them, and every project you start afterwards, from a blank page, the route map or a KML, opens with them. Signed in, they follow your account to any machine. The name, the division and the gradient sections belong to one line and are never part of them, and opening an existing project never changes it. Load my defaults and Reset to factory defaults fill the panel, and nothing changes until Apply.

A line that is already there

Before any geometry is designed the corridor is checked for a railway already joining the two stations. Where there is one the run stops and says an existing connection exists, counts the running lines it has, measures whether its curvature will hold your design speed, and offers to design a doubling, a 3rd line or a 4th line beside it instead of a new corridor — parallel where the old alignment complies and on new geometry where it does not. It proposes; you decide.

Terrain detail is yours

The button picks the ground grid the design is built on — 200, 120, 60 or 30 m — and that is exactly what you get. Under it, what the setting costs for this corridor: tiles, memory and roughly how long. The setting that gives the best detail the corridor carries comfortably is ringed. It is a suggestion, not a decision: pick a finer one and it tells you the price and runs it anyway. A 150 m nala reads anywhere between 2 m and 15 m deep on a 200 m grid depending where it falls between nodes, and the bridge opening follows that — so on broken ground, finer is worth the wait.

What it cannot know

Whether a corridor needs another line is a traffic question, and the traffic is not in a map. Nor is which side of the existing formation the land is available on — that is scored against water and built-up ground and offered as a default, to be overridden in Design considerations → Inclusion.

Alternatives

Keep the line you have and try another one beside it. Alternatives sits at the top of the Plan tab: ＋ Try another route copies the line on the plan as Option B and puts it on the plan, so the next thing you do — drag a point — reshapes Option B and leaves Option A exactly as it was. Click a chip to switch; the other options stay on the plan as dashed lines in their own colours.

What an option holds

Its own plan, profile and stations. The standard, the speeds, the limits and the rates are the project's and are shared, so a change to the design speed re-checks every option and the comparison is of the route and nothing else.

Comparing them

Review → Compare (or Alignment → Alternatives) shows a card per option and the same figures side by side — length, journey time, cost, earthwork, tunnel and viaduct, steepest grade, sharpest curve, check errors — with a ★ on whichever leads. Cost is only compared once every option is priced: a corridor never looked up has no bridges in it and would come out cheapest for the wrong reason.

Other ways to start one

Design Route ▾ → Design an alternative route… runs the route wizard and adds its route as a new option, keeping the one you had. A mountain route search offers Use this route and Keep as an alternative for each route it found, and Keep all.

Undo, save

Switching, copying, renaming and deleting are ordinary edits: Ctrl+Z takes each one back. Every option is saved in the project file. Projects saved with the older Variants open with each variant as an alternative.

An alignment from Google Earth: KML and KMZ

File → Import KML / KMZ… — or drop the file anywhere on the plan — turns a line into a design: straights, intersection points, curves with their radii and transitions, chainage and levels. A path drawn in Google Earth, a track walked with a GPS, a centre line exported from a design package and this application's own Google Earth export all read. The dialog shows the design over the line it came from, IP by IP, before anything on screen changes, and it opens as a new project.

How the line is read

Its direction of travel is plotted against distance along it. On that diagram a straight is flat and a curve is a slope of 1/R, so the straights are found as its flat runs and fitted to the file's own points, each IP is where two of them meet, and each radius is read off the curve between them. A curve that turns one way then the other is split at its point of inflection; one that turns through more than a right angle, as in a hill section, is split so no IP sits at infinity.

Corners and curves

Where the file was clicked at its IPs with no curves drawn, the corners are the IPs and each is given the radius the standard and design speed allow in the room there — the same choice drawing the line on the plan makes. Where it was drawn round its curves, the radii are measured and kept, and marked as measured. A curve too short for its radius to be told from one a quarter larger says so and takes the standard's.

Noise

A handheld track's scatter is measured and averaged out before its shape is read, and a wobble is kept as an angle only if the fixes show it far more clearly than their scatter could. Transition lengths are read only off a clean, dense line; otherwise, and by default, they come from the design speed.

Sections, direction, chainage

A file can hold the boundary, the stations and the alignment together: the likeliest line is ticked, closed rings are marked as boundaries, and ticking several joins them end to end whichever way each was drawn. Chainage can start at any figure and run from either end.

Levels

Fit to the terrain reads the ground along the line from the public elevation model — only the tiles it crosses — and fits a grade line to the ruling gradient, as the router does. From the file's altitudes is offered when the file has real ones; Google Earth writes 0 on every point of a line clamped to the ground, and that is not a level.

Ruling gradient shows the figure the grade line is held to, as 1 in n — the open project's, or the standard's — and takes any other: 1 in 100, 1 in 120. As soon as the ground along the line is read it says whether that gradient can stay on it; where it cannot, it says what the ground asks for, with a button to take it. The figure goes to the project, where Considerations → Design Limits → Ruling gradient shows it as 1 in n too and takes "1 in 120" typed into it as exactly that.

Drawings out of CAD

A centre line exported from Civil 3D or AutoCAD arrives as one Placemark of thousands of pieces — a LineString for every straight and every chord — and is put back together end to end, whichever way each piece was drawn. Arcs the exporter wrote as a handful of long chords (nine is common, standing metres off the curve) are recognised by their equal chords and equal angles and read as the circle through them. A hill loop set out across several IPs is built as one arc on one centre, and the checks report it as one arc continuing, not as missing transitions.

Kilometre posts, stations and other pins

Pins named for a chainage — KM: 12+000, CH 12+345.6 — set the direction and the starting chainage, and the report says how closely the design's chainage reads at every post. A drawing measured on UTM drifts from the ground by the grid's scale, metres over a long line, and the report names the grid when that is why. Station pins (PRO PATHARDI STATION YARD - 1400M) become stations at their chainage; the rest — tunnels, viaducts — become notes on the plan.

What it keeps

The file is kept on the project as the reference line, so the Comparison desk opens on it and shows every metre by which the design departs from what was drawn. Tick Keep the line that is open now to have the old design held beside the new one as an alternative.

Basemaps and georeferencing

The plan view can draw a street map, satellite imagery, topography or shaded relief under the alignment, so a curve can be moved against the ground it actually crosses rather than against an empty grid. Shift+F, or the ⤢ button, gives the plan the whole window for that work.

Where it comes from

A route designed with Design a route already knows where it is. An alignment drawn by hand needs one point tied to the earth: pick the point in the Plan tab and give its latitude and longitude, in decimal degrees or as 27 10 30 N, 78 02 31 E. It is saved with the project.

What it assumes

The plane is treated as a project grid — a transverse Mercator on that longitude, north up, scale 1. The panel reports how far grid distance drifts from ground distance at the point you tied down, in parts per million, so the assumption is visible rather than silent.

Accuracy

Tiles are placed by reprojecting each one's own corners, not by stretching the whole image, so the imagery stays registered to the alignment at any zoom. Basemaps are for context and judgement, not for setting out.

What comes out, in detail

The landing page lists the formats. This is what is inside them.

5 km Plan & Profile sheet packages (.dxf & viewer)

Production-standard Final Location Survey drawing sheets, partitioning any corridor length into 5 km packages. Each carries an upper plan strip with track, land boundaries tagged at 25 m, boxed kilometre posts, curve data apex boxes and bridges; a lower seven-row L-Section data grid — formation, ground, cut/fill, alignment, gradients — with exact chainage vertical callouts; an independent 10 m datum per sheet at 1:25000 horizontal and 1:500 vertical; and a title block carrying project title, division, sheet number and km range. Everything sits on named CAD layers. Viewable on screen with zoom, pan and sheet paging before export.

Station yard conceptual plans (.dxf)

Main running lines, passenger loops, goods sidings and shunting necks; island and side platforms with standard clearance envelopes, each called by the kind it is; 1 in 8.5 and 1 in 12 turnouts with fouling markers; crossovers; 800 m clear standing length loops; 6.10 m track centres for BG running loop clearance. The station side is drawn as it was laid out — the circulating area, the building, the cabin, the parking, the wall around it and the road in — and the signals and station limits are drawn and chainaged with everything else. Vertical plateaus at a maximum 1 in 400 (0.25%) are inserted automatically so a yard never lands on a steep grade, which is what the Indian Railways Schedule of Dimensions requires.

Multi-sheet Excel workbook (.xlsx)

Cover, setting-out table, horizontal curves, vertical curves, civil structures, a cut and fill report with mass-haul balance, land acquisition pegs, the signalling and interlocking schedule, and the compliance report. An active detailed estimate adds component bills, measurements, rate analyses, captured rate sources and linked summaries. Export one component or the complete estimate from its own workspace.

Bridge GADs (.dxf / .pdf)

Prepare spans, supports, foundations and attached wing or return walls in the bridge workspace, then review the plan, elevation, sections and 3D view. A1 GAD sheets carry dimensions, levels, a level and chainage band, a bearing layout, schedules and drawing identity from the saved bridge. Open web girders follow the RDSO 45.7 m and 61.0 m arrangements cited on railway GADs. The DXF has a layer for each element class and is coloured like railway GADs: proposed work red, existing ground black, HFL blue. The drawings retain their preliminary review status; structural design, foundation adequacy, reinforcement and approval remain separate engineering tasks.

Google Earth 3D model (.kml / .kmz)

Terrain-clamped centreline, a 3D rail elevation ribbon, boxed kilometre posts and station yard footprints, for walkthroughs and stakeholder presentations.

LandXML 1.2 alignment model

Clothoid spirals, circular curves, tangents and vertical grade lines in standard LandXML — read directly by Autodesk Civil 3D, Bentley OpenRail and 12d Model.

Hydrology report (PDF) & crossing schedules (CSV)

Every waterway crossing on its own pages behind a separator: the catchment in plan, the IMD rainfall, the RBF-16 or CWC subzone design flood worked step by step, the 25-, 50- and 100-year floods, the waterway and span arrangement, the Bridge Manual class, the flood level, clearances, scour and foundations, and the crossing drawn in elevation. The schedules carry the same figures, with road over/under bridges after minor roads have been rationalised into grade-separated crossings.

What it is not

This matters more than the feature list. The tool produces an accurate, standards-compliant first pass and preliminary design. It is an engineering accelerator, not a replacement for field verification.

Keyboard

Editing

F zoom to extents · Tab / Shift+Tab next or previous point · Delete remove the selected IP · ↑ ↓ in a numeric cell steps the value, with Shift for ten steps · Enter in a table goes down the column, Shift+Enter up · ← → from the edge of a cell to the next · Ctrl/Cmd+K find any command

Files

Ctrl/Cmd+Z undo · Ctrl/Cmd+Shift+Z redo · Ctrl/Cmd+S save · Ctrl/Cmd+O open

Cab ride

Space run or stop · 1 2 3 cab, chase and orbit cameras · ← → nudge 25 m, with Shift 250 m · , . the previous or next thing on the line · Home End either end · R ride the other way · L look ahead again · F full screen · S saves the frame as a PNG · H sounds the horn · Esc closes the open panel, and then the window. Save ▸ Video… (paid plans) makes an MP4 of the line — a teaser, about three minutes of highlights or the whole ride — cut between the cab, the chase, the orbit and cameras beside the line, with the panels, the sound, the commentary and the platform announcements. Drag the picture to look out of the side window — or, from the orbit, to swing round the line — and the wheel changes the lens or closes in. The cut and fill layer colours the earthwork by depth and calls out the deepest cut and highest fill in shot. A dialog owns the keyboard while it is open, so these reach the ride rather than the plan behind it

Cab ride 2 (3D)

Open Review → 3D & cab rides → Cab ride 2 (3D) for the WebGL view. Choose Cab, Chase, Orbit or Lineside; inspect scheduled platforms, foot overbridges, shelters, station amenities, bridges and cutting drainage. These are visual models of the design, not a structural or accessibility approval. The original Cab ride remains available separately. Read the controls and limits.

Account

Sign in on the hosted site to work on projects and use the project hub, with revisions and sharing. A guest demo provides a read-only introduction. Builds without a configured cloud service support local files without an account.

The project hub

The cloud button opens it: everything you have saved, and everything anybody has shared with you, on two tabs with a box to find one by name. Share on one of your own projects asks for an email address and a level — can view opens a read-only copy, can edit saves back into the same revision history. An address with no account yet is held as an invitation and becomes a share the moment somebody signs up with it. You can change a level or withdraw access at any time, and only the owner can delete a project or decide who else has it.

Views

Wheel zooms · drag pans · drag a point in the plan or a VIP in the profile to reshape, with Shift in the profile holding the chainage · Shift+F puts the plan full screen, Esc leaves it · Shift+wheel in the profile changes the vertical exaggeration · double-click empty space in the plan inserts an IP, and in the profile a grade break at that chainage — which is how a gradient over the max length of one gradient limit (5 km by default, on Considerations → Design Limits) is broken by hand · [, or the button at the end of the tab strip, folds the side panel down to its icons and gives the width to the views; any icon opens it again on that table

The profile on a second screen

The window button on the profile's title bar — or Display → Profile on a second screen — moves the profile, the curvature and cant and the mass haul to a window of their own, to put on another monitor; the plan keeps the first window to itself. Everything works there as it does here: dragging, the right-click menu, typing a level, and the keys, undo among them. It opens where it was last left; in Chrome and Edge Other screen sends it to the next monitor and fills it. Back under the plan, the same button again, or closing the window puts the views back. The designer's own window stays open behind it, and pop-ups have to be allowed for the site

The right button, and groups of points

Right-click the plan or the profile for a menu of what can be done where you clicked: add an IP or a grade break there, or select, move or delete the point under the pointer · right-drag draws a box and selects every point inside it · Ctrl-click (⌘ on a Mac) puts a point into the selection or takes it out, and Ctrl with a right-drag adds a box to it · drag any point of a group and the group moves together · Move on the menu picks the points up until a click puts them down, and Esc puts them back · Delete removes the whole selection in one step, keeping the two ends · Esc lets go of a group

Typing a level or a gradient, and regrading to the ground

In the profile, Edit level on a VIP's menu — or a double-click on the VIP — opens its level and the gradients in and out, each typed as 1 in n (or a percentage with %); whichever is typed, only that VIP moves · Edit grade on empty profile — or a double-click on a gradient's label — opens that gradient and the level at either end, with Keep saying which end stays when the gradient is typed · the profile follows as you type, Enter keeps it as one undoable edit and Esc puts it back; a gradient steeper than its leg allows is named before it is kept · Regrade to the ground on the menu of a VIP or a selection puts the levels as close to the ground as the ruling gradient allows — less curve compensation on a curve, and the yard gradient through a station — moving the VIPs either side only where a gradient to them would otherwise break it, and never the ends, a station yard or a locked level · the Grade out column of the VIP table takes a gradient typed the same way, and moves the next VIP to it

Save the project and its survey together

Cloud projects

A cloud save includes the acquired OpenStreetMap corridor features, crossing decisions and the detailed estimate. Reopening a saved survey reuses it instead of repeating the corridor search. DEM terrain tiles can download again. An older project without saved OSM data needs one lookup; save it afterwards to retain the result.

One local .rads file

Save or export a native project as one .rads file containing the project and its available support data. Existing .rads + .radsupport pairs still open when selected together; saving them again produces a single file. A downloaded file contains the data already loaded into the project, not basemap imagery that has never been downloaded.

Apply, then save

Apply estimate makes the edited bill the project's active estimate. Save project writes it to the current cloud or file destination. Exporting a draft workbook does not save the project. Check the Save status before closing the designer. Full saving instructions.

Drawing overlay tools

Beyond the computed alignment, the plan takes manual drafting for constraints and context. Shapes live on layers with specific semantic meaning, rather than just being lines on a screen.

The shape types

The overlay handles basic geometry: line, rect, polygons, note markers, dimension (dim) lines, and deadend buffers. They are drawn in map space, so they move with the terrain, not the viewport.

Measuring

Press M, then drag from one point to the other, or click once at each end. With one end down you can pan and zoom before you click the other, so a measurement can be longer than one screen. Each end snaps to the nearest IP, tangent point, station centre, point on the centre line, or corner or edge of anything drawn. The box around the pointer shows where it will land before you press. Hold Alt to place an end without snapping; Esc cancels a measurement you have started.
The dimension is drawn while you take it, with a readout beside it: the distance, the bearing, ΔE and ΔN, each end’s chainage and offset from the centre line, the distance along and across the line, and, where there is terrain or a survey, the ground level at each end with the rise or fall between them as 1 in N. Select a finished measurement to read the same figures again, and drag either of its ends to move just that end.

Chainage marks

Press P and click on or beside the line to pin a note to that chainage. Within a grab radius of the line it sits on the line; further off it keeps its offset. It is labelled with its chainage and offset, Ch 45+620.0 · 12.0 m L, and whatever you type after it. It is held to the chainage rather than to a place on the ground, so when an IP is moved the mark moves with the line. Pick a mark to type its chainage and offset exactly, or drag it to a new place and it takes the chainage and offset it is dropped at.

Offset lines

Press O, press beside the centre line at the offset you want, and drag along the line to where it should end; a click runs it the whole length. The offset is taken to the half metre and the chainages to the metre. Like a mark it is held to the line, so it follows the alignment. Drag either end to run it further, or pick it to type the offset, the side and the two chainages.

Ground sections

Press G and drag across the ground; the ends snap to IPs, corners and the centre line as a measurement’s do. Pick the section and the ground along it opens beside the rail: the profile, the straight between its two ends dashed over it, and a bar at rail level where it crosses the alignment, with the bank or cutting there. It reads the terrain, or the survey where one is loaded; with neither, it says what to fetch.

Editing what is drawn

Pick any line, rectangle or outline and drag one of its corners to move just that corner. It snaps as a measurement’s end does; hold Alt to place it free. A dead end pressed by a track stands on it and lies along it. When an outline is waiting to be traced, the hint strip asks with Trace and Leave as outline buttons as well as Enter and Esc, and a long press offers the same.

Context layers

notes, sketch, and measure are for visual markup. trace holds reference lines you want to follow. trackwork and existing denote permanent way that is already on the ground, serving as visual constraints when weaving a new alignment.

Router constraints

The avoid and include layers change how the autorouter behaves, and how hard they push is something you set on each area rather than something the layer decides. An avoidance area is weighted by default — a cost per metre, which a pinched corridor may still choose to pay, and which is reported when it does. Marked regulated it is priced the same way but recorded as needing a named authority’s consent; marked prohibited it is not priced at all, and those cells are removed from the search so no weight anywhere buys a way through. Each area can carry a setback in metres and an outer regulated belt, because the statute that constrains an alignment is written that way — the AMASR Act bars construction within 100 m of a protected monument and regulates the next 200 m. Presets for the usual instruments (AMASR, wildlife, forest, CRZ, defence) fill in the distance, the authority and the class.

An inclusion area is a discount: it makes the ground cheaper so the route is drawn towards it, and it cannot on its own oblige the line to go there. Tick the line must pass through this and it becomes an obligatory point instead, with the corridor searched in legs through it. Either way, an inclusion area the alignment misses is reported rather than passed over in silence.

Station yard design

Yards are laid out as conceptual plans directly on the alignment, carrying standard clearance and operating geometry without needing a separate CAD session.

The yard editor workflow

Pick a station and the editor sets out main running lines, passenger loops, goods sidings, and shunting necks. You choose the platform arrangement — island or side — and it enforces standard clearances, such as 6.10 m track centres for BG running loops and 800 m clear standing lengths.

Working in the editor

The window is laid out like a drawing tool. The railway objects are down the left — loops, sidings, crossovers, platforms, stabling, pit, washing and inspection lines, shunting necks and the station buildings — and each one dropped on the drawing lands in the nearest place the section can hold it. The properties of whatever is selected are down the right, and under the drawing are the live checks, the longitudinal profile the yard stands on and a cross-section cut wherever you point the chainage probe. Add parallel track (P, or a right-click on a road) lays a road beside another at a track centre you state; anything closer than the 5.30 m SOD minimum is marked on the drawing where it is, not only in a list. A navigator shows where you are in a long yard, and a chainage typed into the toolbar takes you there.

Generate a yard

Give it a brief — loops, platforms, the longest train, depot lines, goods and catch sidings — and it lays out candidate yards side by side, each one solved and checked, with its length, width and number of turnouts. The platforms go between pairs in one, on the outer faces in another and one of each in a third, because that is the choice that sets how wide the yard is and how passengers reach the trains. Take one and edit from there; undo brings the old yard back.

Turnouts and fouling

The editor models 1 in 8.5, 1 in 12, 1 in 16 and 1 in 20 turnouts, and numbers every one along the yard (T-1, T-2 …) with its hand, lead, lead radius, crossing angle and the speed its turnout route may be taken at. It automatically computes and places fouling markers where converging tracks drop below safe clearance, ensuring the declared standing length is genuinely available for rolling stock.

Plateau grading

A yard cannot sit on a steep gradient. The vertical alignment is automatically checked and flattened into a yard plateau at a maximum of 1 in 400 (0.25%), inserting vertical curves to tie it back to the ruling grade, meeting the Schedule of Dimensions requirement.

The throat is a ladder

Each road takes off from the road immediately inboard of it, not all of them from the main line, so no two sets of switch blades ever stand on the same stretch of stock rail. Because a turnout can only be laid on straight track, the fouling marks step outward as the roads go out — which is why a six-road yard reaches further along the line than a two-road one with the same loops, and why the gradient and radius limits are tested over all of it.

Signals, and the station limits

The signalling follows from the throat once it is laid: the home an adequate distance outside the first points, a starter on each running line at its fouling mark, and the advanced starter beyond the last points, where the block section begins. The distance between them is what each running line can berth — and a loop too short to hold the train the line is planned for is reported with both figures, and lengthened for you.

Export

The finalised layout drops straight into the DXF export, meaning the 5 km sheet packages carry the fully modelled station limits on standard CAD layers, not just a centreline. The signalling and interlocking schedule comes out beside it as a CSV and as a sheet of the workbook: every point with its number and how it is worked, every signal with what it reads over, the berthing lengths, and the equipment the standard of interlocking asks for.

Multiple tracking

When adding lines to a route that is already there, the geometry depends on whether the old line is fit for the new traffic.

Existing line detection

The router checks the corridor for a railway already joining the stations. If it finds one, it measures how many running lines exist and offers to design a doubling, 3rd line, or 4th line.

Speed compliance and realignment

A parallel offset is only drawn where the existing curvature supports the new design speed. Where a curve is too tight, the tool drops the parallel offset and designs a realignment — new geometry on a wider sweep that complies with the standards.

Tie-in points

Where a realignment separates from the old line and where it returns, the tool automatically calculates the tie-in points. This ensures the new track smoothly rejoins the existing formation, keeping land acquisition and earthwork for the deviation to a minimum.

Detailed component estimates

Open Output → Detailed estimate. Start with a blank bill or import a snapshot of the generated design estimate, prepare each work package separately, and combine the included components in one summary. Imported quantities remain fixed until reviewed or reimported.

Separate bills, one summary

Create components for earthwork, individual bridges, track, station buildings, land or other packages. Assign an estimate head, split cash and stores, include or exclude items, and review the component, head and project totals. Project charges are applied once in the combined estimate.

Measurements and rate analyses

Enter quantities directly or use count × length × breadth × depth rows with deductions. A billing divisor converts measured quantities to units such as 100 Sqm. Build resource analyses from material, labour and equipment coefficients, overhead and profit, or record an adopted project rate and its source.

USSOR 2021 and DSR 2023

Search 4,249 catalogue variants from Central Railway USSOR 2021 and CPWD DSR 2023 civil schedules. The estimate reads the project's railway zone and location and preserves the selected source rate, unit and reference. Apply verified local indices or project rates; the Central Railway and Delhi monetary rates are not automatically valid in every location.

Review and export

Missing quantities and rates stay unpriced; provisional allowances and source ambiguities remain visible in Review. Incomplete bills show a priced subtotal. Pro exports include formula-linked Excel workbooks and CSVs for one component or the complete bill, with the active estimate carried into reports. Follow the complete workflow.

Where the numbers come from