If the US-led coalition is to maintain the strategic edge, we must have free and open discussion of strategic issues. It is important that this public discussion maintains precision in terms. This precision is more important as the topic of discussion becomes more tactical. Imprecision in tactical terms can lead to strategic level warning misdiagnosis.
Recently, there has been expert malpractice on the topic of the PRC’s new bridge barges and their tenuous connection to the Mulberry Harbor capabilities deployed during D-Day 1944.
Bottom Line Up Front
The bridge barge is a simpler part of a whole. It is a modest capability increase in the PRC's amphibious lift fleet, particularly in areas of extensive mud flats. Definitely helpful to the PLA but not a change in the overall trend. On X, @TShugart3 does a good job of analyzing the current imagery.
If the PRC were to begin construction of Mulberry harbors, this would be a far more ambitious project. Mulberry harbors are complex and very difficult to maintain in readiness. This would be a key indication that the PLA was ready to invade Taiwan in the next 4 months to a year. It would be a flashing red siren unless the PLA was confident they could maintain the constituent capabilities of a harbor for a long duration.
Bridge Barge Analysis
The tricky problem for attacking amphibious forces is how to deliver combat power onto the beach. The vast majority of ships, vehicles, and supplies in an attacking force cannot actually land on the beach under their own power (even in specialty amphibious forces like the USMC and Gator Navy).

For example, major amphibious L-class vessels like the Landing Helicopter Assault (LHA) and Landing Platform Dock (LPD) cannot directly beach themselves to unload onto the beach - without a port, they require a type of platform known as landing craft or ship-to-shore connectors.
The much discussed PRC Roll-On/Roll-Off semi-civilian ferry ships (ROROs) also require ship-to-shore connectors (SSCs, related to, but not to be confused with the Navy program of the same name).
SSCs come in many forms. One group includes much smaller craft capable of beaching or getting close to the beach and then backing off into the water. These include the small Landing Craft utility (LCU) and hovercrafts that use air like the Landing Craft Air Cushion (LCAC) or the Type 726 Yuyi. The Landing Craft Mechanized (LCM) and Maneuver Support Vessel Light (MSVL) also fill this role. For a WWII example, the Higgins Boat or Landing Craft, Vehicle, Personnel (LCVP) was featured in Saving Private Ryan at the beginning. Tom Hanks’ Rangers would have transferred from a larger vessel to the LCVPs at sea, and then hit the beach.
Some SSCs are exotic. This includes capabilities like the US Army's Modular Causeway System (MCS), US Navy's Improved Navy Lighterage System (INLS), and the PLA's Yupai floating dock. All three of these systems are primarily composed of modular, self-propelled causeway sections (as well as warping tugs, roll-on/roll-off discharge platforms, ferries, etc) which can connect and assemble at sea, motor to the beach, and embed into the sand as an expeditionary pier. Then, other causeway sections or tugs can be used to head to sea, pick up troops, and motor back to the expeditionary pier and re-attach, allowing the troops to drive onto the beach. It is fancy and temperamental. MCS was deployed this summer during the Gaza pier drama.
Of course, a plain old port facility can act as the "SSC" as well, since any vessel up to the port's size restriction can find a berthing and unload onto the dock/wharf/pier. Defenders know this, and will thoroughly sabotage their own ports to prevent use by the amphibious attacker.
A portion of modern amphibious forces also field fully oceanic amphibious armored vehicles, like the PLA's Type 05 and Type 08 platforms. The Type 05 and Type 08 can simply drive straight off the back of a ship, convert the engine power from tracks/wheels to propeller power, and then swim their armored vehicle to the shore, where propeller power is then switched to tracks/wheels again once on the beach. The problem with these vehicles is they cannot swim far - a max of about 15 km/8 km, which means they still require amphibious assault ships, landing craft, or something civilian to carry them most of the way.

Returning to the PLA's recently unveiled bridge barges, these are ostensibly civilian ships (they aren't) with a bow (front) gate that kicks down and releases an extending suspension bridge like a tongue out of a mouth. You can see the tall tower mounted to the front of the ship meant to suspend the retractable bridge. This bow bridge is meant to bite hard onto the beach, providing safe purchase for forces moving onto the beachhead.
If we look at the stern (rear) of the ship, we see another gate. This is a telltale sign that the stern gate is meant to be kicked down and mated to another ship which we will call ship2 (could be any vessel with shallow enough draft to make it close to shore next to the bridge barge). Ship2 can then disgorge its load onto the bridge barge, and then the load can traverse the bow bridge onto the beach.
The design of this bridge barge gives away so much of how the PLA is thinking.
First, even with the existing PLA Yupai (discussed above, one of the modular pier systems), it is very difficult to "drive the spike" of the Yupai, INLS, or MCS bridge onto the beach. The US Army calls this "the Torch." Often, engineering vehicles ashore are required to form a sand berm "female end" for the bridge "male end" to dock into. This is time intensive, and PLA forces would be unable to do this quickly or under fire. The bridge barge can speed this process. This could have been a PLA “lessons learned” from the Gaza pier drama.
Second, this bridge barge is an ugly bitch. With that suspension tower for the bridge, the heavy bridge itself, and the ungainly towers/pilings for the seabed feet (some vessels have four towers, others have six), these barges will be finicky in the surf and and less than seaworthy transiting the strait.
This thing is going to get rocked in heavy swell (bad weather), which is exactly what happened to the D-Day landings in 1944. The PLA understands it really needs a good weather window to land on Taiwan (there are only two good weather windows per year).
Third, the procurement of these bridge barges continues to highlight that the PLA believes middle-spectrum amphibious ships are key to their landing operation. They cannot rely only on fishing trawlers at the low end and proper naval landing ships at the high end; there must be a large contingent of critical but vulnerable support craft which could be high payoff targets for blue forces.
Fourth, these bridge barges can be connected stern-to-bow and bow-to-stern, meaning they can form a long chain working together. This long chain allows the PLA to create a long bridge able to traverse some of the difficult landing zones in Taiwan, which include nasty mudflats girding many of the landing beaches. The Taiwan Army currently believes these mudflats are impassable amphibious terrain.
Fifth, Taiwan is cut by extensive river networks running from East to West. As the PLA landing force attempts breakout, they will inevitably run up against one of these many rivers, whether their objective is Taipei, Taichung, or Kaohsiung. With enough covering fire, area control, or perhaps at night, the PLA could move the bridge barges up a river and install themselves to allow maneuver forces to assault across. Alternatively, the bridge barges could relieve an engineer pontoon bridge force so that the engineers can displace their pontoon bridge and keep pace with the main assault.
Sixth, there are landing areas (particularly in the south) dominated by difficult to traverse rice paddy agriculture. PLA mobility engineers could blow the paddy dikes in a linear fashion, creating a breach point to move the bridge barges inland. This would allow ground forces to bypass unfavorable terrain.
Seventh, the bridge barges would only be one piece of a Mulberry Construction (and may not be employed as such due to their expense and increased mobility).
Mulberry Technical Analysis
The construction of Mulberry Harbors is a completely different process. These are massive moveable port facilities (with their own pierage, docking, amphibious transhipment, defense capabilities, etc) which require major manpower, engineering resources, and operational finesse.
Each Mulberry must be designed not only to the specific hydrography and beach terrain of the target landing area, but must be maintainable and not degrade at the friendly assembly area where the Mulberry waits until it is called into action.
The best example is the namesake, Mulberry A (constructed for the Americans at Omaha Beach) and Mulberry B (constructed for the British & Canadians at Sword Beach), which were custom-designed by the Allies to support the Normandy landings in 1944.
Each Mulberry consisted of two portions, a breakwater and an inner port, and each of these consisted of three major systems.

The Mulberry's breakwater included the 1) Bombardon, 2) Phoenix, and 3) Gooseberry systems.
The Bombardons were massive 250-ton steel beams in the shape of a cross. The bottom and horizontal arms of the cross-shaped beams were designed to flood with an additional 1,500 tons of seawater, bringing the total mass of a deployed Bombardon close to 2,000 tons. Each Bombardon would then be moored and chained in place as the outer breakwater for the artificial port.
The effect was to reduce an 8-foot wave on the seaward side of the Bombardon to a 2-foot wave on the leeward side. Allied engineers calculated this would render a 75% reduction in wave energy on the lee, which could also affect the total depth of water (draft). As we already discussed, draft affects what size of ships are able to traverse that area of sea. Allied engineers wanted to ensure that Liberty ships were able to use the Mulberry, so they had that target draft in mind.
You can see from this example just how complicated the construction of a Mulberry is, and how it must be custom to the landing beach.
The second system of the breakwater was the Phoenix Caisson. These were huge floating hollow concrete flat-bottomed barges that could be sunk in place to form the inner breakwater for the artificial port.
A very specific concrete mix and certain size of aggregate in the mix were required to provide the caissons with the durability required for at least three months of continuous operation until the sea naturally broke them down.
Amazingly, the first person to think of the Phoenix concept was likely Winston Churchill while serving as First Lord of the Admiralty or as Minister of Munitions in 1917. But back to 1944.
Since the top of each Phoenix during operation was a flat and dry concrete surface, Allied engineers didn't let this space go to waste. Multiple pylons and platforms were constructed on each caisson in order to form a fortified battle position for an anti-aircraft artillery (AAA or ack ack) team. This way, the Mulberry could sail into battle with organic air defense which would also be ready as the artificial port was under construction.
As part of the deception plan, each Phoenix could be submerged and re-floated at will. The Allies built the Phoenix systems and then submerged them off the coast of England at night so that German intelligence could not identify them.
The third system of the breakwater was Gooseberry. Only 147 Phoenix caissons could be constructed, leaving a 4.5 mile total coverage gap across both Mulberry A and B. Additionally, Phoenix was large and bulky, so required reinforcement at joints or unexpected areas of high waves.
To fill the gaps, Allied engineers turned to Gooseberry, using obsolete ships to sail across and scuttle themselves in the breakwater gaps where needed.
Each individual ship was called a Corncob. These vessels had their armaments salvaged and replaced with more anti-aircraft artillery to support the Caissons.
On the eve of the invasion, 75 Corncobs were to steam towards the landing beaches and scuttle themselves at the Mulberry sites. The deception plan included basing these individual vessels all over the UK, so as not to mass them into one area and forming an intelligence target for the Germans.
The Mulberry's inner port systems included the 1) Spud Pier, 2) Whale/Beetle Bridge, and 3) PHP systems.
The first system of the inner port was Spud, the pier where ships could unload (a berthing area) that is above water. The Spud piers would sit in the middle of a Mulberry complex and wait to receive ships coming into the artificial harbor to unload.

The sea level could rise by 24 feet or lower by 24 feet at the target beaches, so each Spud had to have at least 50 feet of height adjustment.
The solution was equipping each Spud with four 90-foot legs driven by electric motors. This way, the Spuds could independently raise and lower their height to accommodate different ships and different water levels.
It sounds simple, but the Spud is an amazing piece of engineering. The Spuds had to withstand the side load forces of a 4 knot current simultaneous to the side load forces of the other platforms acting against it. The Spud feet also had to be designed to take advantage of the specific sea bed floor, which could only support 2 tons per square foot. Spuds would also have to deal with waves up to 5 feet high.
The second inner port system was a bridge connecting the Spud to the beach which had to be super flexible. Therefore, a pontoon bridge concept was adopted, with specially designed pontoons called Beetles and specially designed steel bridge sections called Whales. This system is most similar to the modern PLA bridge barge capability.
From Allied beach reconnaissance, it was clear that the Whale/Beetle bridges would have to withstand 160 foot long waves weakened by the breakwater hitting the bridges at an angle.
This meant that adjacent Beetle pontoons could have a 17 foot height difference between them and that adjacent Whale bridge spans could be at a relative angle of 24 degrees. That is a ton of flexibility to have to engineer into a bridge.
To complicate matters further, the tide naturally goes in and out. Based on tidal data, each Beetle required four deployable legs operated with hand wheels. When the tide went out and the water level/draft lowered, the Beetles would deploy their legs to maintain the required uniform bridge height. As the tide came in, each Beetle would stow its legs and begin floating to again retain uniform bridge height.
Whale/Beetle bridges had to be designed to handle a Sherman tank at full combat load, approximately 45 short tons depending on variant. Modern PLA systems would have to be designed to at least 65 tons to handle a ZTZ-99A at full combat load.
Further limitations came in the form of an Allied steel shortage. There was not enough steel to construct all of the Beetle pontoons, so 100% steel Beetles were only used in the beachward sections where friction and damage calculations (mostly from rocks) were highest. Concrete-steel Beetles were used for the seaward side.
The third system was the Pier Head Pontoon (PHP). The problem with the Spuds and Whale/Beetle bridges was that they only constructed one long road to the beach. This is insufficient for unloading massive amounts of supplies and combat power because cargo can only be unloaded in one long line (a slow process with no ability to turn a vehicle around).
Essentially, the Spuds required a massive working space to unload and reorganize cargo for forward movement to the beach. In modern times, we call this amphibious transhipment.
We will not go into details, only to say that the PHPs were subject to the same stress as the Spuds and each PHP was required to float into the Mulberry and attach to a Spud, forming a larger surface area and workspace to make the Mulberry a functional port.
The above is a ton of complexity which I have simplified. There were more critical capabilities invented like Kite anchors, buffer pontoons, LST pierheads, Baker fenders, and shore ramps. There was also the problem of towage across the channel for all of these components.
A Mulberry is a massive, complex, and time-sensitive capability. For more info, please look up the web page "The Crete Fleet."
For Analysts
The PLA, if they are wise, will hide their Mulberry components far up river into continental mainland China, and sprint the assemblies down river into the sea for deployment. A tricky operation. Geospatial analysts should be searching for construction of suspicious looking unidentified vessels/craft. Hundreds to thousands of such vessels/craft will be required for a modern PLA Mulberry.