「Even if you say that, those bastards will bring plenty of food right? They have lots of villages like ours that provide them with food. So with all that, they should have a lot right?」
Roleau unexpectedly brought up a good point. It was true that the Empire would bring as much food as they could. They would bring enough that they might not even need to collect food from the villages along the way.
「Yeah, the Empire does have plenty of food. The issue is, whether they are able to carry all that food at once. Let’s calculate what a single soldier needs per day.」
I said and turned to write ‘Food, Water, Clothes’ on the board.
「First let’s talk about food. Soldiers marching from dawn til dusk will get very hungry. At the very least they will need bread, dried meat, and vegetables. To feed a soldier there needs to be 500 grams of food minimum for a meal, then the minimum number of meals in a day should be set at two. So food for each day will weigh 1 kg per soldier.」
This was the minimum, in reality they would carry more for sure.
「Next is water. This is a necessity for marching. A male human needs 2 liters of water a day when marching or they will collapse. Due to the numbers they will have difficulties resupplying on the way. The areas where they can refill their water is quite limited. Even if they refill at some villages, rivers, or lakes they will have to take enough for at least five days or they run the risk of running out of water.」
Furthermore, river water held its own dangers. There was a good chance that drinking so much river water would cause stomach problems and could even immobilize all 4,000 troops.
If they boiled the water properly there wouldn’t be a problem, but for that they needed to bring fuel and that would further increase their carrying weight. The only place they could reliably and safely secure that much water was from village wells. Furthermore, I could only think of two villages that were large enough and along the way.
Even if they decided to dig their own well, the underground water sources around here were considerably deep and digging a single one would cost them at least an entire day.
「Next is clothing. The least they need are fresh underwear so that hygiene issues don’t spread. That’s at least another kilogram. In short, every soldier needs at least 4kg of goods to survive. For every day after that, excluding the clothes, the weight increases by 3 kg. Five days of supplies comes out to 16kg. Roleau, how many kilograms can you carry while walking easily?」
「Walking til sundown right? I’d say carrying three large bags of wheat all day is my limit. It’s around 30 kg or so.」
「Since a strong guy like Roleau says that, then a normal human soldier can only do around 20kg. This means that each soldier can only carry around 6 days of supplies along with them.」
「Wouldn’t they be fine if they just bring dedicated porters with them to carry their stuff? Or they could bring a bunch of supplies on horse wagons.」
「Of course there are people like that. However, there’s a limit to how many they can bring. They need food and water for them as well, and for horse wagons they need to bring feed and the entire expedition will slow to a crawl. Even if they brought out an entire army to provide supplies and created a line long enough to reach back into the Empire, the frontline army would still need to wait for the supply line to connect and if even one delivery is late then their food will run out. In the first place they’ll need 15,000kg of goods per day. The monetary cost of such a thing is no joke.」
The construction of supply lines are the greatest military issue in this day and age. Once civilization and technology progresses to some degree the required human labor will decrease and the amount of goods will increase. However, in this age it required human labor and could be considered a great headache.
「I doubt they will create a trailing supply line behind them. I suspect, that instead that a solid 30% of their forces will consist only of people transporting food and goods. They will carry the armor and items. Normal soldiers would carry their own goods and once they ran out they would accept food from the porters. From my point of view, their water supply should only last them 10 days even if we assume they refill at a village.」
At that point they will have 10 days to travel 100km before reaching a supply base within distance of Erucy before aiming for us. Forcing an army of 5,000 to travel 100km in 10 days…was unreasonable but not impossible.
Arriving at they relay station they would pick up their arms and armor. Without they weight of their equipment they would be able to carry more supplies and with some additional planning they should have enough supplies.
They wouldn’t need to wait for their supply team to catch up since after the battle with Erucy they could wait for them or return to meet them. Also, this method would allow them to only bring enough goods for a one way trip.
I’m sure they thought that, if by any chance they ran out of supplies part way, then all they needed to do was wait for a delivery from the relay point. Once the battle was over they could calmly wait for enough supplies to make the return trip.
The Empire’s marching plans should basically turn out like that.