Which other files need to be changed to reduce the width of the tracks? I have changed the t.railTrackWidth = 0.600, this makes no visible change to the width.
Any help would be most welcome 
.
Here is the track.lua file:
function data()
local t = { }
t.name = _("600mm tracks")
t.desc = _("600mm narrow gauge tracks")
t.categories = {"600mm"}
t.icon = "ui/tracks/600mm.tga"
t.yearFrom = 0
t.yearTo = 0
t.shapeWidth = 2.5
t.shapeStep = 1.5
t.shapeSleeperStep = 8.0 / 12.0
t.ballastHeight = .2
t.ballastCutOff = .1
t.sleeperBase = t.ballastHeight
t.sleeperLength = .20
t.sleeperWidth = 1.2
t.sleeperHeight = .08
t.sleeperCutOff = .02
t.railTrackWidth = 0.600
t.railBase = t.sleeperBase + t.sleeperHeight
t.railHeight = .06
t.railWidth = .07
t.railCutOff = .02
t.embankmentSlopeLow = 0.75
t.embankmentSlopeHigh = 2.5
t.catenaryBase = 5.917 + t.railBase + t.railHeight
t.catenaryHeight = 1.35
t.catenaryPoleDistance = 20.0
t.trackDistance = 5.0
t.speedLimit = 30.0 / 3.6
t.speedCoeffs = { .85, 30.0, .6 } -- curve speed limit = a * (radius + b) ^ c
t.ballastMaterial = "track/ballast.mtl"
t.sleeperMaterial = "track/sleeper.mtl"
t.railMaterial = "track/rail.mtl"
t.catenaryMaterial = "track/catenary.mtl"
t.tunnelWallMaterial = "track/tunnel_rail_ug.mtl"
t.tunnelHullMaterial = "track/tunnel_hull.mtl"
t.catenaryPoleModel = "railroad/power_pole_us_2.mdl"
t.catenaryMultiPoleModel = "railroad/power_pole_us_1_pole.mdl"
t.catenaryMultiGirderModel = "railroad/power_pole_us_1a_repeat.mdl"
t.catenaryMultiInnerPoleModel = "railroad/power_pole_us_1b_pole2.mdl"
t.bumperModel = "railroad/bumper.mdl"
t.switchSignalModel = "railroad/switch_box.mdl"
t.fillGroundTex = "ballast_fill.lua"
t.borderGroundTex = "ballast.lua"
t.railModel ="railroad/tracks/single_rail.mdl"
t.sleeperModel = "railroad/tracks/600mm_single_sleeper_base.mdl"
t.trackStraightModel = {
"railroad/tracks/600mm_2m_base.mdl",
"railroad/tracks/600mm_4m_base.mdl",
"railroad/tracks/600mm_8m_base.mdl",
"railroad/tracks/600mm_16m_base.mdl",
}
t.cost = 55.0
t.order = 100
t.minCurveRadius = 24.0
t.minCurveRadiusBuild = 40.0
t.maxSlopeBuild = 0.175
t.maxSlope = t.maxSlopeBuild * 1.6
t.maxSlopeShape = t.maxSlope * 1.25
return t
end
