Index: train_cmd.c
===================================================================
--- train_cmd.c	(r‚vision 4906)
+++ train_cmd.c	(copie de travail)
@@ -112,6 +112,7 @@
 	if (v->u.rail.cached_power != power) {
 		v->u.rail.cached_power = power;
 		InvalidateWindow(WC_VEHICLE_DETAILS, v->index);
+		InvalidateWindow(WC_VEHICLE_VIEW, v->index);
 	}
 }
 
Index: rail_cmd.c
===================================================================
--- rail_cmd.c	(r‚vision 4906)
+++ rail_cmd.c	(copie de travail)
@@ -29,6 +29,7 @@
 #include "newgrf.h"
 #include "newgrf_callbacks.h"
 #include "newgrf_station.h"
+#include "train.h"
 
 const byte _track_sloped_sprites[14] = {
 	14, 15, 22, 13,
@@ -864,11 +865,20 @@
 
 		/* Update build vehicle window related to this depot */
 		if (IsTileDepotType(tile, TRANSPORT_RAIL)) {
+			Vehicle *v;
 			Window *w = FindWindowById(WC_BUILD_VEHICLE, tile);
 			if (w != NULL) {
 				WP(w,buildtrain_d).railtype = totype;
 				SetWindowDirty(w);
 			}
+
+			/* Update vehicule power */
+			FOR_ALL_VEHICLES(v) {
+				if (v->type == VEH_Train && IsFrontEngine(v) && v->tile == tile && v->u.rail.track == 0x80) {
+					TrainPowerChanged(v);
+				}
+			}
+			InvalidateWindow(WC_VEHICLE_DEPOT, tile);
 		}
 	}
 
Index: train_gui.c
===================================================================
--- train_gui.c	(r‚vision 4906)
+++ train_gui.c	(copie de travail)
@@ -445,6 +445,9 @@
 			/* Draw the pretty flag */
 			DrawSprite(v->vehstatus & VS_STOPPED ? SPR_FLAG_VEH_STOPPED : SPR_FLAG_VEH_RUNNING, x + 15, y);
 
+			/* Draw a lock if the train can't be started */
+			if (v->u.rail.cached_power == 0) DrawSprite(SPR_LOCK, x + 15, y);
+
 			y += 14;
 		}
 	}
@@ -594,7 +597,8 @@
 		break;
 
 	case -2: // click start/stop flag
-		DoCommandP(v->tile, v->index, 0, NULL, CMD_START_STOP_TRAIN | CMD_MSG(STR_883B_CAN_T_STOP_START_TRAIN));
+		if (v->u.rail.cached_power != 0)
+			DoCommandP(v->tile, v->index, 0, NULL, CMD_START_STOP_TRAIN | CMD_MSG(STR_883B_CAN_T_STOP_START_TRAIN));
 		break;
 	}
 }
@@ -917,6 +921,8 @@
 
 			SETBIT(w->disabled_state, 12);
 
+			if (v->u.rail.cached_power == 0) SETBIT(w->disabled_state, 5);
+
 			/* See if any vehicle can be refitted */
 			for (u = v; u != NULL; u = u->next) {
 				if (EngInfo(u->engine_type)->refit_mask != 0 ||
@@ -983,6 +989,7 @@
 
 		/* draw the flag plus orders */
 		DrawSprite(v->vehstatus & VS_STOPPED ? SPR_FLAG_VEH_STOPPED : SPR_FLAG_VEH_RUNNING, 2, w->widget[5].top + 1);
+		if (v->u.rail.cached_power == 0) DrawSprite(SPR_LOCK, 2, w->widget[5].top + 1);
 		DrawStringCenteredTruncated(w->widget[5].left + 8, w->widget[5].right, w->widget[5].top + 1, str, 0);
 		DrawWindowViewport(w);
 	}	break;