Repairing LI - case study
Posted: Sat May 03, 2014 7:04 am
Base: Changsha
LI damaged: 144
Supply expended for repairs: 144,000
Repair time: 12/8/1941 - 5/5/1942
Repairing 1 damaged LI costs 1,000 supply, thus it takes 1000 days to break even on this investment. That is the general rule of thumb. I tried to gauge whether this rule of thumb is sound using Changsha as the case study.
During 12/8/1941 - 5/5/1942 period I will expend 144,000 supplies to repair 144 LI there. This newly repaired LI starts generating new supply as soon as it is repaired. Each day the number of this newly produced supply will be growing by one and added to the supply produced beforehand in the following matter:
1:1
2:1+2
3:3+3
4:6+4
5:10+5
6:15+6
7:21+7
8:28+8
9:36+9
etc.
After 144 days, this new supply pile will reach 10,050 supply points. So I have expended 144,000 supplies, but the repaired industry have already repaid 10,050 supplies. So 133,950 supplies have to be repaid from 5/5/1942. This will happen after 930 turns (133,950 / 144 daily new supply in Changsha) on 19 November 1944. This is the day I break even. If the war lasts until 31 March 1946, the Changsha investment will give me a windfall of 67,248 supplies (144 supplies x 467 turns).
To conclude: the 1000 days rule holds, albeit modified downwards due to new supply generated during the repair period. In order to ripe the rewards of your investment, you need to start repairing as soon as you can, preferably starting on turn 2. The repairs make most sense if you plan to hold the repaired base until the end of the war, preferably protected from enemy intervention i.e. air raids, which can damage the industry.
LI damaged: 144
Supply expended for repairs: 144,000
Repair time: 12/8/1941 - 5/5/1942
Repairing 1 damaged LI costs 1,000 supply, thus it takes 1000 days to break even on this investment. That is the general rule of thumb. I tried to gauge whether this rule of thumb is sound using Changsha as the case study.
During 12/8/1941 - 5/5/1942 period I will expend 144,000 supplies to repair 144 LI there. This newly repaired LI starts generating new supply as soon as it is repaired. Each day the number of this newly produced supply will be growing by one and added to the supply produced beforehand in the following matter:
1:1
2:1+2
3:3+3
4:6+4
5:10+5
6:15+6
7:21+7
8:28+8
9:36+9
etc.
After 144 days, this new supply pile will reach 10,050 supply points. So I have expended 144,000 supplies, but the repaired industry have already repaid 10,050 supplies. So 133,950 supplies have to be repaid from 5/5/1942. This will happen after 930 turns (133,950 / 144 daily new supply in Changsha) on 19 November 1944. This is the day I break even. If the war lasts until 31 March 1946, the Changsha investment will give me a windfall of 67,248 supplies (144 supplies x 467 turns).
To conclude: the 1000 days rule holds, albeit modified downwards due to new supply generated during the repair period. In order to ripe the rewards of your investment, you need to start repairing as soon as you can, preferably starting on turn 2. The repairs make most sense if you plan to hold the repaired base until the end of the war, preferably protected from enemy intervention i.e. air raids, which can damage the industry.