The Consist That Stringlined on a Curve
A long train pulled its mid-cars straight off the inside of a curve. Here is why lateral coupler force — not the grade alone — lifted them off the rail.
Read the post-mortemFailure analysis
Case Studies in What Went Wrong
Every one of these is a post-mortem, not a glamour shot. A real HO scale failure — a train that stringlined, a turnout that arced, a car that climbed the rail — traced from the symptom you see to the physics underneath to the fix that actually holds. The point is to reason about the layout as a system, so you can diagnose your own failures instead of guessing.
Each study links the Lab tool that puts a number on the problem and the glossary terms that name the forces at work.
The Turnout That Arced and Stalled Locos
A metal-frog turnout threw sparks and stalled short-wheelbase locos. The root cause was a frog powered against the point setting — a dead short waiting for a wheel.
Read the post-mortemThe Car That Climbed the Rail on a Tight Curve
A long passenger car picked the outer rail and climbed off on an 18-inch curve. Nadal’s limit and the car’s overhang explain exactly why.
Read the post-mortem
Put a number on it
From post-mortem to prevention
Each failure here is something the Lab calculators help you avoid up front — grade and pull, clearance, radius, wiring. Reach for them before the next build, not after the derailment.
Name the forces
The terms behind the failures
Stringlining, Nadal’s limit, overhang, power routing — the glossary derives each one from the physics, so the case studies read as diagnosis rather than jargon.