Index: src/engine.cpp
===================================================================
--- src/engine.cpp	(revision 24948)
+++ src/engine.cpp	(working copy)
@@ -654,10 +654,11 @@
 	e->company_avail = 0;
 
 	/* Don't randomise the start-date in the first two years after gamestart to ensure availability
-	 * of engines in early starting games.
+	 * of engines in early starting games. Also don't randomize the start-date if the NO_RANDOM_INTRO_DATE
+	 * flag is set.
 	 * Note: TTDP uses fixed 1922 */
 	uint32 r = Random();
-	e->intro_date = ei->base_intro <= ConvertYMDToDate(_settings_game.game_creation.starting_year + 2, 0, 1) ? ei->base_intro : (Date)GB(r, 0, 9) + ei->base_intro;
+	e->intro_date = ((ei->base_intro <= ConvertYMDToDate(_settings_game.game_creation.starting_year + 2, 0, 1)) || (HasBit(ei->misc_flags, EF_NO_RANDOM_INTRO_DATE)))   ? ei->base_intro : (Date)GB(r, 0, 9) + ei->base_intro;
 	if (e->intro_date <= _date) {
 		e->age = (aging_date - e->intro_date) >> 5;
 		e->company_avail = (CompanyMask)-1;
Index: src/engine_type.h
===================================================================
--- src/engine_type.h	(revision 24948)
+++ src/engine_type.h	(working copy)
@@ -158,6 +158,7 @@
 	EF_AUTO_REFIT = 4, ///< Automatic refitting is allowed
 	EF_NO_DEFAULT_CARGO_MULTIPLIER = 5, ///< Use the new capacity algorithm. The default cargotype of the vehicle does not affect capacity multipliers. CB 15 is also called in purchase list.
 	EF_NO_BREAKDOWN_SMOKE          = 6, ///< Do not show black smoke during a breakdown.
+	EF_NO_RANDOM_INTRO_DATE        = 7, ///< Do not randomize the vehicle introduction date.
 };
 
 /**