Design Document:Engineering

Bridges

Bridges are structures used for crossing rivers and areas that are impossible to lay track on. Bridges begin with heads which take track to minimum depth this bridge can be built over. Heads are block of concrete/brick.

Heads are default for every bridge. Track or road is what player will lay on the head top.

Bridges are made of piers and spans.

There are two types of a span – first span and middle span. First span connects piers to the heads. Middle spans connect piers themselves.

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The scheme is:

Yellow – 1’st span

Red – pier

Blue – middle span

Definitions are

Bridge as a whole:

   * name – text name of the bridge
   * startyear – year of fist availability
   * endyear – year of discontinuation
   * lengthmin – minimum length of the bridge
   * lengthmax – maximum length of the bridge
   * width – width of the bridge (in tiles) (half and quarter tile also possible)
   * maxspeed – maximum speed attainable on this bridge 

first span definition

   * length – length of the span (in tiles)
   * cost – cost of building the span
   * maintenance – cost of maintaining the span for a year
   * raze – cost of removing the span
   * time – time of building the span, in seconds real-time 

middle span definition is the same

pier definition includes

   * cost – cost of building the pier
   * maintenance – cost of maintaining the pier for a year
   * raze – cost of removing the pier
   * time – time of building the pier, in seconds real-time 

Bridges are built symmetrically – piers and spans are mirrored from both directions (eg the same pier or span is used on both sides).

Tunnels

Tunnels are an effect of-auto-landscaping. If the landscape exceeds certain amount the game will enter a tunnel and also will enter ‘underground’ mode. Then the player may commence building (all structures and tiles below above certain height will cease to be shown, also ‘hidden’ tiles are showed for those that will cause exiting underground mode, and those that will allow further building of the tunnel.

All structures that can be built over the ground, can be built underground (that is stations, etc) but one thing to note – catchment area is also limited vertically.

Elevations

Elevations are ‘negative’ tunnels. They allow to rise track/road without landscaping. Elevations allow twisting, turning etc. Maximum elevation height is around 4-5 metres above the ground.

Elevation has either a form of a brick support (no speed limit), a wooden trestle (cheap, but limited speed) or a steel trestle (speed limited, but not severely, cheaper then brick, more expensive then wood).