45 mm Track gauge
39.5 mm Wheelset back-to-back (same as Aristo loco wheelsets)
3 mm Flangeways at guardrails
4 mm Flangeways at frogs (for wider range of wheelset gauges)
3 mm Flange depth at frogs
27 mm Kadee #1 Centerline height from railhead
30 mm Kadee #820 mounting pad height from railhead
25 mm Aristo knuckle centerline to railhead
TURNOUT DIMENSIONS
Lead = length from point to frog. Below based on A.R.E.A. specs:
No. 4....13.6 in Prototype 36 ft 3.75 in
No. 5....15.25 in 40 ft 7.75 in
No. 6....17.0 in 45 ft 3.5 in
No. 7....23.6 in 62 ft 11.75 in
No. 8....25.6 in 68 ft 4.5 in
CROSSTIE DIMENSIONS - MODEL AND PROTOTYPE
Prototype vs 1:29 calculated P&C Aristo Regular Aristo USA Style
8 in width = 9/32 in (7.0 mm)
9 in width = 11/32 in (7.9 mm) 9 mm (3/8") 10 mm 7.9 mm
24 in spacing = 13/16 in (21 mm) 25.4 mm (1") 25.4 mm (1 in) 21 mm
22 in spacing = 3/4 in (19.3 mm)
20 in spacing = 11/16 in (17.5 mm)
CLEARANCES
7.25 in Minimum overhead (from railhead)
5 in Side clearance (straight track)
7 in Side clearance (curves)
5 in Track center minimum (yards)
6 in Track center (mainline)
6.5 in Track center (mainline curves over 5 ft radius)
7 in Track center (mainline curves under 5 ft radius)
LOCOMOTIVE AND CAR LENGTHS (not including couplers)
32 in Aristo RDC (calculates to 77.3 ft)
29.5 in Aristo heavyweight cars (71.3 ft)
26.7 in Aristo SD-45
22 in Aristo RS-3
17 in Aristo 40-ft cars
12.7 in MDC hopper cars
TALLEST AND WIDEST ROLLING STOCK
Tallest: Aristo steel caboose smokejack - 7.25 in
Widest (straight track): USA baywindow caboose
Widest (inside on 4-ft radius curves): RDC - 3.75 in from track centerline
Widest (outside on 4-ft-radius): RDC - 3.75 in from track centerline
TYPICAL TRAIN LENGTHS
7 ft Mogul and 3 Bachmann passenger cars
11 ft Engine and 6 40-ft cars
20 ft Engine and 12 cars
34 ft 2 engines and 25 hopper cars
RADIUS VERSUS DEGREES OF CURVATURE
1 degree = 1 degree of change per 100 ft of track
degrees = 2 x arcsin (50/Radius)
Degree Radius 1:29 rad. HO rad.
1 5730 ft 198 ft
4 1433 ft 49 ft
8 717 ft 25 ft
10 574 ft 20 ft 80 in
15 383 ft 15 ft
20 287 ft 9.9 ft 40 in
25 231 ft 8 ft 26.5 in
30 193 ft 6 ft 7 in 22 in
Prototype rarely has curves sharper than 20 degrees.
PROTOTYPE LOCOMOTIVE WEIGHTS AND HORSEPOWER
Model HP Weight 1:29 Calculated (tonsx2000/29x29x29)
44 ton 350 44 tons 3.6 lbs
SW-1 600 100 tons 8.2 lbs
NW-2 1000 123 tons 10.1 lbs
RS-3 1600 124 tons 10.2 lbs
GP-30 2250 127 tons 10.4 lbs
SD-45 3600 200 tons 16.4 lbs
RDG GS-3 Pacific: 164 tons = 13.5 lbs
RDG A-5a 0-4-0: 55 tons = 4.5 lbs