Although he was the commander of the fleet, Bai Zhizhan always believed that it was not only the towering warships that determined the combat effectiveness of the navy, but also many auxiliary ships.

The more famous ones are fleet tankers, which later became fast combat support ships.

Among the many auxiliary ships, the status of the self-propelled floating dock should not be underestimated, and even ranked ahead of other engineering vessels.

The reason is simple.

A self-propelled floating dock can provide services for several, or even dozens of warships, thus greatly increasing the in-flight rate of warships.

The floating dock can be used not only to repair damaged warships, but also to provide other services.

For example, the maintenance of warships on the front line, especially in the depths of the ocean, which is extremely far from the mainland and has a serious lack of supporting facilities.

In a sense, a self-propelled floating dock is a shipyard that can sail.

Although it cannot be used to build warships, it is definitely more than enough to repair and maintain warships.

In actual use, the floating dock is used to provide daily maintenance for ships eighty percent of the time, and there are not many opportunities to repair damaged warships.

The problem is that the cost of self-propelled floating docks is ridiculously high.

Before the outbreak of the war, self-propelled floating docks were the most expensive special engineering vessels, which were not only expensive to build, but also to be costly in their daily maintenance and use.

It was in this way that the Imperial Navy procured two.

In peacetime, self-propelled floating docks are mainly civilian, basically have nothing to do with the navy, and rarely provide services for warships. Even if the warship has a serious failure in the open sea, such as the power equipment or propulsion system not working properly, the navy will choose to send a tugboat or have a fellow ship tow it, because the cost of towing the warship back to the military port for repairs is much lower than using a floating dock.

If self-propelled floating docks had been built in the way they had been before the war, there would certainly not have been much of them.

Fortunately, the Imperial Navy solved this problem in a very ingenious way.

It's not special, it's the sectional construction method.

To put it simply, in addition to the engineering section and the power section being built separately, the maintenance section of the self-propelled pontoon is designed and built according to a unified standard, and is assembled according to actual needs when used, so as to provide services for warships of different sizes and tonnage.

For example, for aircraft carriers and battleships, 8 maintenance sections are required, with a carrying weight of 50,000 tons and a docking compartment length of 300 meters. If you want to service large warships such as heavy cruisers, you only need to cobble together 4 or 6 maintenance sections, carry less than 30,000 tons, and dock length between 180 meters and 240 meters. If it is reduced further, the weight of the load can be controlled within 10,000 tons by piecing together two maintenance sections, and the length of the dock compartment can be shortened to 120 meters, which can only serve small warships such as destroyers.

The key is that all maintenance sections are subject to uniform standards.

Not only the dimensions are completely identical, but the connection ports are all unified specifications, which is convenient for random patchwork and combination in actual use.

In the actual construction, in order to save costs and speed up the construction, the shipyard used thin steel plates to build the hull, then poured cement into it, and finally welded a floating tank with drainage function on the outside of the hull as needed, which shortened the construction time of the maintenance section by two-thirds in one fell swoop.

In fact, it is this construction method that makes the self-propelled floating dock a "big road cargo".

Otherwise, it would not have been possible for the Imperial Navy to build more than 20 self-propelled floating docks in just over two years, making them "self-help" maintenance depots all over the place.

Among other things, the "Beihe" and "Nanjiang" were first repaired at the self-propelled floating dock in Shiquan City before returning to the imperial mainland.

Because the preliminary maintenance was in place in time, the shipyard maintenance time of the two fast battleships was shortened to 3 months.

If all goes well, they can be re-programmed into the battle sequence at the end of the year and appear by the carrier's side as a bodyguard.

However, the value of self-propelled floating docks is mainly reflected in escort operations.

If anything, this has to do with the current predicament of the Imperial Navy.

Before the outbreak of the war, because there were few routes to protect, and no one thought that the route to Posha Bay could be opened so smoothly, and no one even thought that they could grasp the strategic initiative after the war, and because there was the possibility of fighting several heavyweight opponents at the same time, it was necessary to give priority to ensuring the construction of aircraft carriers, fast battleships, and heavy cruisers, so the Imperial Navy has not paid much attention to anti-submarine escort, and even if a lot of destroyers have been built, they are mainly large ocean-going destroyers that accompany the fleet's activities.

There are very few anti-submarine destroyers that can really be used in escort operations.

Of course, not only the Imperial Navy, but the navies of all countries had similar problems.

The reason is also very simple, in the era of the treaty, in order to ensure the superiority of the main fleet, the navies of various countries did not pay attention to the second-class warships used for escort operations.

In addition, after the end of the last war, construction replaced confrontation, and the Navy did not have a good time.

Like the navies of other powers, the Imperial Navy mothballed a large number of escort destroyers built in the last war, especially in the later periods, in peacetime.

In order to cope with the treaty, some of them were also disarmed, and weapons such as artillery and torpedoes were dismantled.

In fact, these old destroyers, which are generally more than 20 years old, were the main escort force in the early days of the war.

Although the old warships were mothballed, the dilemma of insufficient troops in the early stage of the war was effectively alleviated, many fundamental problems were not solved.

Among them, the most headache for the navy is indispensable maintenance.

After taking Shiquan City and entering the Fanyan Ocean, when it was necessary to protect the fleets sailing back and forth, the Imperial Navy found that there was a serious lack of naval bases that could support escort ships along the way, and the military port of Shiquan City could not provide services for all escort warships.

It was obviously not feasible for the escort ships to return to the empire mainland every few months.

Just sailing back and forth takes a lot of time.

The key is that daily maintenance does not require the use of shipyard equipment, nor does it require professional skilled workers, and many jobs can be done even by officers and men of the fleet.

What is needed is some special tools that are not available on the ship.

In addition, it was necessary to get the battleship out of the water, remove the parasites from the bottom of the ship, and carry out flaw detection and inspection of the hull.

It was in this situation that the self-propelled floating dock acted as a floating base.

The Imperial Navy deployed 12 ships, or about 60 percent of the self-propelled floating docks, in Colombo to serve escort warfare.

It is with these self-propelled floating docks that the escort fleet to and from the North Sunset Ocean can remain efficient.

In terms of contribution, the value of these 12 self-propelled floating docks is equivalent to 10 escort aircraft carriers and 50 anti-submarine destroyers!

Of course, self-propelled floating docks are also available to freighters who were attacked by submarines and got lucky enough to reach Colombo.

To put it bluntly, if there were no 12 self-propelled floating docks, under the existing investment, the Beifanyan Ocean route would have been paralyzed long ago. If the route is to be kept open, it will need to increase the investment at least twice, and more warships will have to be drawn from the Guia Ocean.

With insufficient troops, will the Imperial Navy still be able to triumph over the Guia?

From this point of view, it is not too much to evaluate these auxiliary vessels made of cement.