Posted May 31, 2017
*edited to add more info*
Summary -
1) Select your target and view the target recon photo
2) Determine your bombing route
2c) Squadron Commanders select your bomb configuration
3) Calculate target length
4) Use your speed, height, and target length to find the ms delay time setting using the bomb delay calculator.
1) Recon Photo
a) The Bomber commander can just look up the target photo.
b) The Squadron commander can select their target in the Operations Room. It's best if you've sent your own recon flights on a previous mission to obtain flak and fighter intelligence (or get a report rebuilding from prior damage).
Doc's v7th recon photos can still be found through the wayback machine.
https://web.archive.org/web/20120723131953/http://glewis.us/v7th_Recon/
2) The bombing route
All target photos from the v7th are orientated so the top of the photo is North. This is important for determining how the bombs will fall.
a) Bomber campaign - your route is set for you. View the route map and figure out how you will overfly the target. I use a protractor over the map on the monitor. REMEMBER - v7th photos up is north - be sure to take that into account when measuring for target length.
b) Squadron campaign - You get to plan route direction and height. Using the v7th photo create your waypoints so you can align your bomb run for maximum coverage. The protractor will come in handy here too. Don't forget to match the route you intend to fly to the bomb run angle you've selected with the photo.
c) In the Squadron campaign you can select your primary and secondary bomb loadout. Use AP for hardened targets like sub bases. Incendiaries are meant for oil refineries. I used cluster on airfields. There is an image of the bomb damage table attached.
3) Calculate target length
With the size of the target in the photo and the photo itself you can translate that to the length of the target in feet. This link starts with how to estimate target length:
http://www.angelfire.com/fl5/bombardier/IntervalometerCalculations.htm
The Bomber campaign is usually not along the best route covering the length of the target. You will often cross for a short run. Squadron commanders can plan a route along the longest line of the target.
I have trouble with rail bridges though. Rather than plan your route along the length of the bridge, you might want to cross at a diagonal angle.
4) Determine ms delay time
When you know the target length you just divide that by the number of bombs you are carrying. That will give you the bomb spacing required to hit the length of the target (if you have good aim!)
There were two mechanical calculators and a table shared back in the v8th/Bombs-Away days. The calculators were designed for Warbirds 2.0 and they can still be found online.
This is the template to build a circular slide rule: http://www.errthum.com/troy/warbirds/b17/BTDC_v1.pdf
This is the template to build a linear slide rule: http://www.bobheffner.com/overlays/bomrule1.pdf
I've also attached a low quality scan of the bomb delay calculator spreadsheet.
a) Bomber campaign - Default altitude is 15000 ft and the usual speed is 150mph. Take the bomb spacing, speed, and altitude and you can read the intervalometer setting on the slide rule or consult the Bomb Delay Calculator table.
b) Squadron campaign - Same as Bomber campaign except double check the altitude. I usually set my altitude for somewhere between 22000 - 27000 feet.
c) for both, adjust your calculation if you have your radio operator call for an evasive action altitude change after you pass the initial point and before you reach the bomb release point.
Summary -
1) Select your target and view the target recon photo
2) Determine your bombing route
2c) Squadron Commanders select your bomb configuration
3) Calculate target length
4) Use your speed, height, and target length to find the ms delay time setting using the bomb delay calculator.
1) Recon Photo
a) The Bomber commander can just look up the target photo.
b) The Squadron commander can select their target in the Operations Room. It's best if you've sent your own recon flights on a previous mission to obtain flak and fighter intelligence (or get a report rebuilding from prior damage).
Doc's v7th recon photos can still be found through the wayback machine.
https://web.archive.org/web/20120723131953/http://glewis.us/v7th_Recon/
2) The bombing route
All target photos from the v7th are orientated so the top of the photo is North. This is important for determining how the bombs will fall.
a) Bomber campaign - your route is set for you. View the route map and figure out how you will overfly the target. I use a protractor over the map on the monitor. REMEMBER - v7th photos up is north - be sure to take that into account when measuring for target length.
b) Squadron campaign - You get to plan route direction and height. Using the v7th photo create your waypoints so you can align your bomb run for maximum coverage. The protractor will come in handy here too. Don't forget to match the route you intend to fly to the bomb run angle you've selected with the photo.
c) In the Squadron campaign you can select your primary and secondary bomb loadout. Use AP for hardened targets like sub bases. Incendiaries are meant for oil refineries. I used cluster on airfields. There is an image of the bomb damage table attached.
3) Calculate target length
With the size of the target in the photo and the photo itself you can translate that to the length of the target in feet. This link starts with how to estimate target length:
http://www.angelfire.com/fl5/bombardier/IntervalometerCalculations.htm
The Bomber campaign is usually not along the best route covering the length of the target. You will often cross for a short run. Squadron commanders can plan a route along the longest line of the target.
I have trouble with rail bridges though. Rather than plan your route along the length of the bridge, you might want to cross at a diagonal angle.
4) Determine ms delay time
When you know the target length you just divide that by the number of bombs you are carrying. That will give you the bomb spacing required to hit the length of the target (if you have good aim!)
There were two mechanical calculators and a table shared back in the v8th/Bombs-Away days. The calculators were designed for Warbirds 2.0 and they can still be found online.
This is the template to build a circular slide rule: http://www.errthum.com/troy/warbirds/b17/BTDC_v1.pdf
This is the template to build a linear slide rule: http://www.bobheffner.com/overlays/bomrule1.pdf
I've also attached a low quality scan of the bomb delay calculator spreadsheet.
a) Bomber campaign - Default altitude is 15000 ft and the usual speed is 150mph. Take the bomb spacing, speed, and altitude and you can read the intervalometer setting on the slide rule or consult the Bomb Delay Calculator table.
b) Squadron campaign - Same as Bomber campaign except double check the altitude. I usually set my altitude for somewhere between 22000 - 27000 feet.
c) for both, adjust your calculation if you have your radio operator call for an evasive action altitude change after you pass the initial point and before you reach the bomb release point.
Post edited June 15, 2017 by jayarrell
