The S4 line number was used by the Berlin S-Bahn between December 1997 and June 2002. The line acted as a temporary route for the re-opened parts of the Berlin S-Bahn ring until the complete ring was fully re-opened in June 2002. The ring is now served by lines S41 and S42.
The numerical value of s4 in Chaldean Numerology is: 3
The numerical value of s4 in Pythagorean Numerology is: 1