Dangyang Castle is different from Gangneung Castle in that it is far away from Mizusawa and is separated by a Nagasaka slope in the middle.

According to Wei Minsheng's vision, it was planned to use the soil and stones of the Changban slope to fill the water.

Only by filling in the swamp puddles in Yunmengze that cannot be footed can mechanized equipment be useful.

The purpose of taking Dangyang City is to arrange construction nearby, and find a relatively safe place for those who work in Changban Slope to stay.

In order to reduce everyone's workload, Wei Minsheng took the high-definition digital map provided by Guangliang Surveying and Mapping Company to compare the approximate altitude measured by the altimeter to select a suitable starting site.

Since the altitude of Gangneung Castle is between 20 and 50 meters, and the highest altitude of Nagasaka Slope is more than 200 meters, there is a difference of about 150 meters between the two points.

Therefore, Wei Minsheng planned to find a valley with an altitude of about 80 meters on the slope of Changsaka, and then lay steel rails, and use the freight compartment of the train to use the altitude difference of more than 30 meters to transport soil and rock.

The rail is filled in a section of roadbed and then installed in a section, extending all the way to Gangneung City.

Because the rail is deliberately laid with a slight slope, the cargo compartment filled with earth and stone is converted into kinetic energy under the action of gravity, and the earth and stone can be sent to the end of the rail without any traction on the way.

In order to improve the capacity and efficiency of transporting earth and rock, the rails were laid into a double carriageway.

One for the transport of earth and stones, and one for the return of empty wagons.

At the end of each of the two lanes, a herringbone track is laid for carriages to change lanes.

The wagons laden with earth and gravel are unloaded at the end of the herringbone track and then return to the top of the herringbone track at the loading point via another lane.

After loading the earth and rock, enter the full load area and wait for the departure command to proceed to the next cycle.

In order to better control the speed of the train and to return the empty cars to the higher loading points during this cycle, a tractor is deployed every few cars.

The power system of this tractor has been modified by Wei Minsheng, and the front and rear wheels are jointly driven by two sets of power systems.

The internal combustion engine uses a diesel engine that has been removed from the scrapped heavy truck, and although the rated power is only 235 kilowatts, the torque can be increased under the action of the gearbox, and it is no problem to tow these empty cars to climb a gentle slope.

Moreover, as long as the train moves, it does not use much torque under the action of inertia.

The other set is a motor drive, and its power source is a supercapacitor bank composed of supercapacitors through series and parallel.

The capacity of the capacitor bank can drive an unladen train for about ten kilometers alone under the condition of full output.

This combination can be regarded as a special hybrid locomotive.

The electric drive system can also be used as part of the braking system, as it becomes an energy recovery device when the power supply is stopped.

As long as it is not an emergency braking, the fast charging and discharging performance of the supercapacitor can almost achieve more than 90% energy recovery.

The number of charging and discharging of supercapacitors is basically more than hundreds of thousands of times, and there will be no obvious performance attenuation, and the service life is far from the best lithium battery on the market.

Since the charging and discharging process of supercapacitors is always a physical process, there is no chemical reaction.

Therefore, its performance is very stable, with high safety factor, good low temperature performance, long life and maintenance-free, which are far from being matched by batteries that use chemical reactions.

Electric double-layer supercapacitors have a large internal resistance, so they can be charged directly without load resistance, and if there is an overvoltage charge, the capacitor will open the circuit without damaging the device, which is different from the overvoltage breakdown of aluminum electrolytic capacitors.

At the same time, electric double-layer supercapacitors can be charged without current limiting compared to rechargeable batteries.

Charging without limiting current and voltage, long service life, stable performance, low temperature impact and almost negligible number of charge and discharge times are simply tailor-made for energy recovery.

As for the problem of smaller energy density than batteries, it is not a problem at all when used on a tractor frame with a capacity of up to 60 tons.

In order to achieve the best energy efficiency, the tractor uses the high torque of the diesel engine to move the entire train when it starts with the empty car being towed.

Once the appropriate speed is reached, the motor is switched to maintain the speed of the train.

Since there is no need for an electric motor to output power during the most power-hungry start-up and acceleration phases, a lower load can allow an empty train to travel more than 30 kilometers at a lower load.

When the train is about to enter the waiting area before the loading area, the motor enters the energy recovery stage, converting the kinetic energy of the train into electrical energy and storing it.

Before entering the loading area, there is a small section with a large slope, which is an acceleration zone deliberately set by Wei Minsheng.

When a load area filled with earth and gravel ready trains depart, they can easily reach the right speed on this section of track without power.

However, this steep section of the road also became an obstacle to the return of empty cars.

In order to alleviate this problem, Wei Minsheng installed a winch in the loading area, and used the winch to pull the tractor and empty carriage parked under the steep slope to the loading area for soil and rock loading operations.

A fully loaded train only needs to release the brakes and then take advantage of the slightly larger slope in front of the fully loaded waiting area to increase the speed of the heavily loaded train.

In the process of transporting the earth and rock to the other end of the track, most of the road is recuperated by electric motor braking, and then the power is stored by supercapacitors.

In a complete cycle of earth and rock transport by the train, with the exception of a small amount of diesel fuel during the start-up phase of transferring the empty cars back to the loading area, the rest of the road is almost entirely run by the electrical energy stored by the supercapacitors.

The unloading area is on both sides of the herringbone track that extends in the direction of Gangneung City, and the flow of people pushing trolleys to transfer the unloaded earth and stone on both sides of the track to the designated location.

After the length of the roadbed paved at the top of the herringbone track exceeds the length of one section of rail, the herringbone track is removed, and the herringbone track is supplemented after adding the rail in the middle, so as to realize the extension of the track.

During the re-laying of the tracks, the fully loaded trains can be unloaded with waiting time without affecting the progress of other links.

The soil and rocks unloaded in the middle of the track are no longer used to raise the roadbed, but are directly used to fill in the water on both sides of the track.

When the track was repaired outside Gangneung Fortress, it was the beginning of the large-scale Pyeongtaek field reclamation movement.