After Zhuang Xiaoman went out, Fan Keqin roughly recalled his thoughts and began to study the plan again. After a while, Zhuang Xiaoman handed over a piece of information sent by Kong Xinran, the first secretary of the intelligence department, to Fan Keqin again.

This is the information sent back by the military commanders in several coastal port cities. Until now, no trace of the small Japanese warship has been found. Of course, this is not surprising, because the devil warships have already sailed away from the Xiamen wharf after the supply is completed, and according to the calculation of distance and course, they are in the "three non-docking" zone in the coastal waters at this time, so the "observation points" set up by the Military Command and Security Bureau along the coast will naturally not be able to see these warships. This is a routine report, and it doesn't mean anything if you don't find it.

Fan Keqin put away a few drawings that he had studied and drawn, and handed over the materials to Zhuang Xiaoman again, asking him to send them to the Procurement Section of the General Affairs Office. Let them buy a few more sets.

In this way, Fan Keqin began to prepare this plan non-stop. Time flies very quickly when people get busy, and in this way, a week goes by in the blink of an eye. Almost everything that needs to be prepared, it is already ready.

After repeated experiments, the magnetic mine that Jiang Bin and Du Shengli was responsible for was no longer occupied by four water injection tanks in addition to the original charge department, but changed to occupy five. In this way, the depth fixing device in the re-zero position remains motionless as soon as it enters the water. It is directly two meters below the water level, and at this time, it is only necessary to adjust the depth fixing device for a partition, so the mine will remain three meters below the water surface for snorkeling.

An increase in the charge means an increase in power. All of them are two sets of detonation systems, which can be described as double insurance. As long as one of these systems is operational, the mines will inevitably explode.

It's the same with the timing devices, all of which are two sets. And Jiang Bin and Du Shengli also came up with a very good way to prevent the timer from seeping, that is, use wax to thickly coat the timer, and then use the grease burned by linoleum paper to drip all the crevices again.

With two layers of waterproofing, the timers used for experiments have been lying in the water for three days, and they are still operating very normally.

The training of frogmen was difficult at the beginning. In fact, armed swimming also existed in this era. But it's basically a name, and there are really very few troops who train like this. Mainly after high-intensity training, the amount of food for soldiers has increased greatly and they need nutrition, which warlord is willing to eat and drink openly?

It's pretty good enough to keep you fed and not hungry. In this case, Lao Chiang's Central Army may be better, but it is only reflected in the fact that the equipment is better than that of other local armies, eating and drinking...... I can only say, it's okay. But to train a lot is tantamount to a dream.

Fortunately, the twelve frogmen chosen by Fan Keqin grew up by the river or the sea since childhood. Isn't there a saying that is good? Those who drown know how to water.

These dozen brothers have not drowned so far, which shows that the water is really good. But after that, these people all entered the workplace, so naturally it was impossible to swim like when they were children, and they didn't have that condition.

However, swimming is also the type that once you learn it, you will never forget it for the rest of your life. The twelve frogmen had already regained their senses after a day of training in a piece of water designated by Fan Keqin to be blocked. There were three boys with the best water nature, and even one of them went down and came out of his head on the other side of the river.

Seeing Fan Keqin in his eyes, he felt that these people were watery, although the time of holding their breath was definitely not as good as their own. But human talent alone is never enough. This is mainly due to the fact that the situation in the sea water is inevitably different from that in the river.

In addition, the dock of the big ship even extends several hundred meters from the shore. And you can't really dive a few hundred meters vertically from the dock of a little devil or a puppet government handle, you have to dive from a place where the defense is most lax, or even far away. He remembers the later world record that a person could dive and swim back and forth for several hundred meters without any breathing equipment.

But this is conditional, first, the person is in a calm pool. Second, before the official start, this person has to take oxygen for a long time to keep the oxygen content in his blood to the highest level. Thirdly, this person has been trained in this area all year round.

Fan Keqin doesn't think that his frogman is better than the world record holder a few decades later. After a series of most scientific preparations and a lot of training, they can only dive a few hundred meters in a calm swimming pool. Still not up to their own requirements. For this reason, Fan Keqin specially made a set of diving equipment himself.

The reason why people are human beings is because human beings can make and use equipment in large quantities, not to mention, people have to rely on themselves. In fact, equipment is also made by people, and there is really no shame in using equipment made by humans themselves.

For example, someone has been practicing martial arts for ten years, and another person has spent a year making a clay gun at home, and after the two people meet, this person puts the person who practices martial arts with one shot, and you must not say that the other party is opportunistic and uses foreign objects to win the other party.

A loser is a loser, and don't make any excuses. If you are a true hero, you have to learn a lesson, this time you know the power of firearms, then you also start to learn this knowledge, and strive to build a better, stronger range gun, and strive to surpass the opponent, this is the practice of real heroes.

So it's really normal to use all kinds of equipment. Don't be superstitious about the human body being able to fight the superweapons invented. Otherwise, you're going to die a miserable death.

A few days ago, Fan Keqin asked Zhuang Xiaoman to hand over the thing to the purchasing department to buy, which was a set of underwater breathing apparatus designed by himself.

In fact, in this era, there are already such things as diving suits. The kind that can work underwater for a longer period of time is too bloated, a bit like a spacesuit, with a thick breathing tube attached to it, like a can of super armor.

This thing Fan Keqin can't let his frogmen use, the first is that it's too bulky. The reality is that frogmen need to be underwater for at least a few hundred meters, or even thousands of meters. In this way, the canned wetsuit consumes too much physical energy. The second is that it is not flexible enough. They also have to move with mines underwater, and they also need to set up timing devices, etc., and canned diving suits cannot be operated at all. The third is, if the distance is too far, how long does the breathing tube need to be? The longer it is, the heavier it is.