The East Coast wilderness in May is full of stunning late autumn scenery. On the banks of the Merlin River (San Miguel, named after the abundance of plum trees planted by the immigrants) on its banks, more than 500 new French immigrants are working with the original inhabitants (300 Ming and 100 Charruea) to build a pier pier.

The newly established Meilin Port Wharf of the Executive Committee will be an important transfer station for domestic north-south transportation in the future. In the future plan, the port of Merlin will be both an inland lake port and a railway station. Both the Meilin Port Wharf and the railway station are under the direct jurisdiction of the Ministry of Communications, where there is a large-scale transshipment yard and storage base for transshipment or temporary storage of materials from south to north.

Rusty steel tracks stretch out of the dock (and railway station) yard and wind their way to the southwest, disappearing into the horizon. This steel track, which is currently under construction, is the famous Mianmei Line (Cotton Farm Township - Meilin Port) Railway in the East Coast Republic, which has a total length of more than 80 kilometers and is extremely expensive. Not only were two of the five major construction bureaus under the Ministry of Communications stationed here to carry out arduous railway construction projects, but even the No. 1 Machinery Factory, Ping'an Iron and Steel Plant, Henan Timber Processing Factory, West Lake Timber Processing Factory, Dayuhe Arsenal, Northern Arsenal, Building Materials Company, Inland River Transportation Company, War Department, Ministry of the Interior, and other units were mobilized to fully guarantee the construction of the entire railway.

And right next to the railway station, several huge factories stand alone. There is a wooden sign hanging at the door of the factory, on which are written in black ink "Southern Vehicle Factory of the Ministry of Communications". At this time, the gates of the factory were closed, and several police officers of the Ministry of Internal Affairs were on guard at the door. And inside the plant. The roar of a huge machine was ringing non-stop.

Inside the machine shop of the Southern Vehicle Plant. Several large-scale lathes are rumbling under the drive of steam engines, and the high-speed rotating cutter heads are turning the 12.5-meter rails fixed to the table to make them more accurate. This kind of turning is extremely costly, but who has kept the East Coasters from finding the existence of chromite today? Without metals such as chromium, tungsten, and manganese, high-quality alloy bits can only be a pipe dream.

The processed rails are stacked next to them, and a dozen workers are transporting them to a wooden flatbed wagon, assisted by a small steam crane. After filling a few rails, the driver of the carriage drove the carriage out of the workshop and along the tracks to the outside of the factory. Then turn onto the already laid part of the Mianmei Line railway and transport the rails towards the construction site in the south. Of course, some horse-drawn wagons that pull the rails will also transport some of the rails to the docks, and then lift the rails onto the small river steamers that are currently temporarily used by the wooden trestle. These small steamers will transport the steel rails to the Cotton Farmer Fort Wharf in the south, and then transport them to the construction site by rail wagons like this side, where they will be used to lay the railroad for the workers of the Fourth Bureau of Communications and Construction.

This kind of carriage, specially designed for the track, was produced by the carriage workshop of the Southern Depot Factory. There are several models of this track-specific carriage, including four-wheeled, six-wheeled, and even eight-wheeled heavy carriages. Corresponding to the number of wheels, the number of horses should also increase proportionally. The carriages used steel flanged wheels, and each two wheels were connected together by an axle. It's called a wheelset. The distance between the wheelsets is strictly controlled within the specified range of deviations (less than 1500 mm gauge) to ensure that the wheels do not derail under the road.

Limited by the current level of machining (lack of high-precision grinding machines) and material constraints. Instead of bearings, conventional sliding friction is used between the axle and the wheel. In this case, the technicians of the Ministry of Transportation do not have a good solution, they can only choose to add wax, grease and other lubricants to the axle for lubrication to reduce the wear and tear of the vehicle.

And the bottom of the cabin is also creatively installed with some shock absorbing springs. The spring is made of copper, heated at a high temperature (850 degrees) for a period of time, then quenched in vegetable oil at 40-60 degrees, taken out and removed after a few minutes, and then put into the furnace for tempering (400-450 degrees, lasting five minutes), and then put into 20 degrees of water after the last time. The spring is evenly elastic and durable, and can be used for a long time without losing elasticity. Of course, it was still limited by the material - the lack of some rare metals made it impossible to make a highly elastic alloy copper, and the spring life produced by this method was much shorter than that of modern times. But for now, it can only be like this, let's use it first, at least this is a technology far ahead of this era.

The brake of the carriage was a tread shoe made of cast iron. The brake shoe is opposite to the wheel tread through the transmission part, when the driver is about to arrive at the destination and needs to slow down or need to stop urgently because of an accident, then carry out manual braking, and at this time the brake shoe will hold the wheel tightly under the effect of the transmission part, and the vehicle will slow down or stop by friction. In this process, the huge kinetic energy of the vehicle is converted into huge heat energy through friction, and the temperature of both the wheels and the brake shoes will rise sharply. At this time, if the material is not very good, it is likely that there will be problems, resulting in cracks on the surface of the wheels or brake shoes. However, in the opinion of several designers of the Southern Vehicle Factory, the speed of the existing rail carriages and early steam trains is not very high, and the speed is about tens of kilometers per hour, in this case, the use of cast iron brake shoes is not a big problem.

The carriages are standard wooden and are not divided into front and rear. A number of hooks are installed on both sides to facilitate the attachment of the towing reins of the horse.

At present, the Southern Vehicle Factory has produced eight experimental four-wheeled rail carriages, four of which have been allocated to the south and four of which have been left for trial operation in Port Merlin. In general, the results of the trial operation are acceptable, and the newly designed and produced vehicles will definitely have such and such problems at the beginning, but the technicians and craftsmen of the vehicle factory have eliminated them in time, and carefully noted the reasons and times of each failure, so as to better improve the vehicles in the future.

Torricari, a senior researcher at the Academy of Natural Sciences and now a citizen of the East Coast Republic of China, was at first puzzled by how his fellow travelers had designed a freight carriage so elaborately – or rather, troublesomely. In his opinion, a horse-drawn carriage for pulling goods does not need to be so complicated at all, and many parts can be completely simplified in design. He didn't understand why the traversers would make it so complicated, because it would be more expensive to manufacture, more troublesome to maintain, and of course there would be more failures. Because a lot of parts are added, the corresponding failure points will also increase, which is a very clear reason.

However, after Qi Yongjie, the designer and director of the Southern Vehicle Factory, told him the supreme instructions of the Executive Committee and the Government Council, Torrey was immediately excited. Because Qi Yongjie told him that the executive committee decided to start trying to develop a steam locomotive, that is, the steam engine was used as the locomotive to provide power, and at the same time, many carriages were connected together to form a train, and the steam locomotive pulled the train forward. Because the steam locomotive can theoretically provide a lot of power, this vehicle, which is called a "train" by the designers, will be very efficient in carrying both goods and people, and can easily pull hundreds of tons of goods.

Torricelli is not a mediocre man without vision. On the contrary, he is very intelligent, has a sharp eye, and has a strong hands-on ability. He soon discovered that a considerable number of legendary "train" techniques are used in a series of rail carriages produced by the Southern Rolling Stock Factory, such as flange wheel technology, carriage shock absorbing spring technology, brake shoe brake device technology, and coupler buffer device technology for connecting between two carriages - this technique is still Torricari himself participated in a while ago, he and a group of locksmiths buried their heads in research for several months, after many designs, manufacturing, trials, improvements, and trials. After improving such a painful but happy cycle, the coupler buffer device that meets the requirements of the superior was finally developed.

Of course, in Torricelli's view, there is still a long way to go to develop a steam locomotive at this stage. First of all, the high-pressure steam engine that is used as the core to provide power, as far as the existing steam engine with a maximum cylinder pressure of 0.8 megapascals is concerned, regardless of its performance and reliability, but the output power is probably still a little too small. It's not that the steam engine can't drive the train, but it can only drive the light-loaded train, and if there are too many wagons or too much cargo to be carried, the train will be ridiculously slow. So, in the end, it was necessary to continue to develop steam engines with a higher output output – and the technicians in the boiler shop of the First Machine Plant were already working on this.

In addition to the core high-pressure steam engine, the Southern Vehicle Plant also had to overcome a series of technical obstacles. For example, the steam locomotive frame, the running mechanism (involving a series of techniques such as moving wheels, slave wheels, guide wheels, axle boxes, bogies, traction devices, etc.), in addition to designing a coal water car. Moreover, the design of the steam engine may need to be optimized, whether it is the cylinder seal or the valve actuation device, the design must be reconsidered and optimized to maximize the output power of the steam engine.

All in all, it's a long process, and there are countless technical difficulties to overcome. If the train is really successfully developed, then it can almost be clearly declared that the industrial level of the East Coast Republic of China has once again reached a new level. Fortunately, there is no hurry to cross the crowd now, everyone slowly researches and tries to produce, this is a long-term process of accumulation of techniques, and I don't believe that it will take five, ten or even twenty years to break through these technical barriers. (To be continued......)