Table

Date !	Gauge !	Axle load !	Country	Railway	Remarks
1830	1,435	2.18 t	UK	L&M	XYZ
Wbbey West	444	Burren	Abbey	Ballyvaghan	SSS
Acres	387	Tulla Upper	Feakle	Tulla	HHH
Zcres	253	Burren	Drumcreehy	Ballyvaghan	KKK
Acres	166	Ibrickan	Kilmacduane	Kilrush	MMM
Addergoole	114	Inchiquin	Kilkeedy	Corrofin	AAA

1830 - Rainhill Trials - 2ton 3cwt axle load (2.18kg/m) (Stephenson's Rocket) - 32 km/h

1888 - Sierra Leone Government Railway - 15 kg/m rail and lighter - 5t axle load - 20 km/h
1894 - Addis Ababa - Djibouti Railway -
- 20 kg/m rail - 12t or heavier at lower speed
- 25kg/m - ??t
- 30kg/m - 14t
- 36kg/m - 17t ^[1]
- 40 kg/m - ??t ; rail being replaced in 2010
1894 - Lokalbahn, Bavaria - 10t initially

So long as the width of the base of the rail, or timber sleepers are in use, lighter rail can be replaced with heavier rail.