Specification	Headwaters HOTrak	NMRA-HO	Comments
Number of Mainlines	2	2
Position of Mainlines	5 & 7 inches	5 & 7 inches	Measured from front of module
Module Width	24" minimum 30" standard 36" maximum	24" standard 36" maximum	36" is about the maximum arm reach
Module Length	48" minimum 72" standard 24" increments	24" minimum 24" increments
Block or DCC	Block	Block
Skyboard	Rear 14" high	Rear 14" high	The length of the skyboard (1/16" less than the Module Length at each end)
Rail Height	50"	40"
Height Adjustment	±1"	±1"	2" total adjustment
Minimum Mainline Radius	32"	32"
Mininum Mainline Switch	#6	#6
Maximum Mainline Grade	3%	3%	Use of grades may restrict length of trains and require the use of more locomotives or power units. Grade must be returned to -0- 6 inches from module interface.
Minimum Siding Radius	24"	24"
Minimum Siding Switch	#4
Maximum Siding Grade	4%
Rail Code	100 Nickel Silver	100 Nickel Silver	Flex Track or Hand Laid. No sectional, fiber ties or brass rail.
Track Setback from End of Module	4 1/2"	4 1/2"	9 inch "fitter" used to join rails between modules.
Center Lines on Curves	2 1/2"	2 1/2"
Track Centers for Parallel Tracks	2"	2"
Minimum Parallel Tangent Track Length	3"	3"	The distance from the end of the bridge track at the interface to the first deviation in mainline, i.e., a switch, curve or crossover, etc.
Skirting Color	Cotton duck canvas attached with velcro, edges sewn and pleats along length.		Available at Quality Supply, Dillon. 4 ft. wide $1.65/lin ft 5 ft. wide $2.25/lin ft 6 ft. wide $2.50/lin ft
Front Guard Height	6 inches		Edges smoothed to prevent cuts.
Back Drop Color	Behr "Montana Sky" 41E2		Hand painted or commercial back drops are encouraged.
Track Ballast Color
Foliage Colors	Green Tan		Vary color mix to approximate various seasons/climate.
Front Fascia & Framework Color
Rail & Tie Color			Very Optional
Power Poles
Switch Brand & Type	Peco Electrofrog		Chosen for reliability.