yellow warning T.I's

[Marcel L.]

Hi,

in night raid report no. 348 (11./12.6.1943), targets Dusseldorf, Duisburg etc. are mentioned. The plan of attack of Dusseldorf includes the information that

En route to the target, yellow warning T.I's were to be dropped by Oboe Mosquitos [at specific coordinates]. The marking was to be maintained by Lancaster backers-up, aiming yellow T.I's at existing yellows.

I wonder why these warning T.I's were dropped (during other raids too). What was the warning for? Did they not show the German nightfighters the route?

Can anybody explain this to me?

Thanks.

Best

Marcel

[David Wallace]

Nothing in the 109 Squadron ORB about the specific duties on the Düsseldorf attacks but 109 Squadron often did “route marking” using Oboe, it was the norm to use yellow TIs for that. The bomb loads in the night raid report suggest that after dropping the route markers the Oboe Mosquitos went on to mark the aiming point since they carried both yellow TIs along with the red TIs used for the primary marking at the aiming point.

[Marcel L.]

Hi David,
thanks for your reply.
The coordinates mentioned in the Night Raid Report do not fit to the routes of the aircraft. I think there is a mistake in the coordinates.
Do you think it is correct that the route markings where normally dropped at turning points? During this raid, the crews had to change direction east of Aachen in a northern direction to Dusseldorf.
Best
Marcel

[PNK]

Probably not related but I did think on some raids, probably in occupied countries that civilian populations were given a warning which may have been TIs.

[Marcel L.]

Hi PNK,
thanks for your reply and your idea, what it could have been meant for.
Marcel

[David Wallace]

It’s an interesting question and I think PNK’s suggestion would be a case where they might use yellow TIs but these were dropped in Germany so its unlikely they were warning civilians in this case. France would be different. In most cases where Oboe crews were route marking, the ORB states that for each aircraft and gives the position they marked. It also appears that the yellows on June 11/12 were not dropped using Oboe since those drops do not appear in the Oboe Ground Station ORBs, so they were likely dropped using dead reckoning. These were early days for Oboe and they were still experimenting. The position the warning TI’s were dropped is about 50 miles from Dusseldorf which was the usual distance from the target they began their target run and in the right direction from the ground stations. The position they were supposed to be at to hear their call sign, switch on their Oboe set and begin their target run was called the “waiting point” and was a pinpoint in the sky that was difficult to find out of range of Gee. My guess is the yellow TI’s were dropped to show the Oboe Mosquitos the approximate position of where they were to pick up the beam and begin their target run. There were lots of new Oboe crews being posted in to 109 Squadron and they were about to bring on 105 Squadron as a second Oboe squadron due to the ever expanding demand for Oboe.

[Marcel L.]

David,
thanks for your reply and the interesting thoughts.
May I ask, how you got the point of dropping the flares 50 miles of Dusseldorf? The coordinates in the Night Raid report do not seem correct to me, or I make a mistake by entering the dates in google earth. By doing so, the droppoint is in the north sea far of the route ... :-(
Thanks.
Marcel

[David Wallace]

Marcel - I show the drop point near Dahlem Germany 90 km sw of Düsseldorf. I then measured the approximate distance from that point to where the Oboe Ground Station at Hawkshill Down was. Since the Oboe beam was always an exact distance from the ground station Düsseldorf should be that same distance. Both measured at 379 km from the ground station. This is approximate because I don’t know the precise aiming point and I used the approximate location of the ground station at Hawkshill Down but I think that it indicates the position the yellow TIs were dropped was the beginning of the Oboe beam and the aiming point in Düsseldorf was the end of the beam.
Using the Night Raid Report photo plots I have a better estimate of where the aiming point is and I used a more accurate position for the ground station, the distances are within 1.5 km of each other.

[Marcel L.]

David,
thanks for your explanation.
I have problems understanding the text because of my poor English and the details of Oboe. Maybe you can answer me the following question, hoping that I understand it, sorry.
1. What did you mean by writing: I show the drop point near Dahlem Germany 90 km sw of Düsseldorf. I then ... Did you use the coordinates for the warning T.I shown in the Night Raid Report 53°40`N 06°55'E, which I think is wrong because it is far away from the routes? Or maybe I made a mistake using google earth to find these coordinate ...
2. After studying the interpretation report and a map of it, the aiming point in Dusseldorf must be close to: 51°14'8.86"N 6°47'8.65"E. Does that help?
Thanks again.
Best wishes.
Marcel

[David Wallace]

Marcel - I was using 50N so I was way off in determining the drop position. I have no clue why they would mark there, it doesn’t seem to relate to the target or route. Sorry for the bad information.