In late 2018, the Australian Defense Force requested tenders for Land 400 Phase 3, their program to replace their inventory of M113. This follows the order of over 200 Boxer 8×8 CRVs, in August last year, to fulfil Land 400 Phase 2. The program calls for buying of up to 450 Infantry Fighting Vehicles (IFVs), as well as a supporting set of Manoeuvre Support Vehicles in nine different configurations.
The request for tender was closed on March 1st, 2019, and soon after, four major defense concerns confirmed they had submitted bids: General Dynamics Land Systems Australia, Hanwha, Rheinmetall, and BAE Systems.
The contract states that each IFV must use a 30x173mm cannon and mount a remote weapons station and anti-tank guided missile. The decision to standardize on these features was to maintain commonality with Land 400 Phase 2 vehicles, which also utilize those three features.
However, this may prove to be a mistake. While the 30x173mm caliber is popular, seeing use across NATO on a variety of frontline IFVs, it is starting to be considered to be undergunned in the face of newer heavy IFVs being fielded by Russia and China. As the final Land 400 Phase 3 decision is expected in 2022, potential adversary IFVs with heavier armor could be entering service around the same year.
Many IFVs submitted to the Land 400 trials were “downgraded” from their original cannons. Hanwha’s submission, the “Redback” is a variant of the K21 IFV, which uses the K40 40mm cannon in South Korean service. Similarly, the BAE submission is a variant of the British Ajax, which uses a cased-telescoped 40mm cannon. The CV90 is more flexible, but latest variants adopted by Estonia have been in the larger 35mm caliber, as opposed to 30mm.
But, the Australian government may hope to preserve interoperability with the US, which appears to be largely sticking to 30mm. The Stryker Dragoon continues to be procured with the 30mm cannon, and the Marines are also in the process of buying 30mms for their Amphibious Fighting Vehicles. But the specific cannon being bought for both of these applications, the Bushmaster Mk 44, has the option for being upgraded to 40mm caliber.
What a larger caliber could bring to the table is increased performance from high explosive shells, especially airburst ones. Penetration can be improved on dedicated 40mm guns such as the L/70 Bofors used on Swedish CV9040s and the K40 cannon on K21s, as they use longer calibers like the 40x365mm, however the Mk44 conversion 40mms do not achieve significantly higher velocity for better penetration, as they are far shorter, utilizing the 40x180mm caliber.
As for the other features of the IFVs being adopted, there’s not enough information publicly available to piece together a proper comparison. But, some further requirements of the project may be inferred from an article in Defense Technology Review about Hanwha’s submission, the AS21 Redback IFV.
The article mentions that Hanwha’s K21 was originally designed to counter Russian BMP-3s, of which South Korea has a few to conduct testing on. The Redback was designed to be more beefy and powerful to counter the newer T-15 Armata IFVs.
The hull was enlarged and ground clearance raised to give the Redback increased mine and blast protection. Frontal armor was also vastly increased, however whether it is enough to be proof against just the newer Russian 3UBR8 30mm AP rounds or the new 57mm caliber that could be fitted to T-15 Armatas is unsure.
The trade off for the increased protection is increased weight. The Redback is not amphibious, unlike the K21, and weighs 40 tons, just a few tons shy of the T-90 main battle tank.
The turret mounts the usual 30mm cannon and ATGM launcher, but also has provisions for active protection systems. 3D mockups of the Redback show it with AESA radar panels on the turret faces, similar to the Armata, which could be used to detect oncoming projectiles.
The AS21 Redback is designed to accommodate three crewmen and eight dismounts, fewer than the M113 it replaces, but on par with other IFVs being submitted for the contract.
Other IFVs being submitted for the contract appear to have similar weights to the AS21. This could potentially limit the strategic mobility of the IFV, preventing extensive deployment of the type in any conflict not occurring on Australia itself. However, the Land 400 contract requires that the IFV be able to fight and keep up with Australia’s inventory of M1A1 Abrams tanks, meaning that strategic mobility concerns regarding the IFV should be considered within the context of the combined arms formation it likely will be structured with.