Description
The Atlas 561 is an HO Code 83 #4 Custom-Line Mark IV left-hand turnout — the current-generation tight-radius turnout for yard ladders, industrial sidings, and any spur that doesn't need mainline geometry.
#4 geometry. A #4 frog has a 1-in-4 ratio (frog angle ≈ 14°15′), which translates to about a 15-mph scale speed through the diverging route and an extremely short turnout overall — ideal where space is tight, such as the classic 6-track yard ladder where #4 turnouts let you stack tracks on 2"–2.5" centers without burning real estate. The trade-off vs. a #6 (Atlas 505/506) is restricted speed: cars wobble through the divergent route faster than a scale 20 mph, so reserve #4s for yard and industrial spur work and use #6s on the mainline.
Mark IV Custom-Line is the current Atlas turnout generation — blackened metal frog (powerable, better wheel-pickup, more prototype-looking), rivet-less switch points (smoother throw, fewer derailments), exact same geometry as the Code 100 Custom Line so existing Code 100 layout plans drop straight into Code 83 builds. Works with under-table switch machines (Tortoise, Atlas) or standard above-benchwork manual/remote machines (Atlas #65/66).
Specifications
- Scale: HO
- Rail Code: Code 83 nickel-silver
- Type: #4 Custom-Line Mark IV turnout
- Direction: Left Hand
- Frog Angle: #4 (≈14°15′, 1:4 ratio)
- Frog: Blackened metal (powerable)
- Brand: Atlas
- SKU / Item Number: 561
Pairs Well With
- Atlas 560 — Code 83 Wye Custom-Line turnout (yard throat companion)
- Atlas 505/506 — Code 83 #6 LH/RH Super-Track turnouts (mainline)
- Atlas 65/66 — Code 83 remote switch machines