LMP‑2017 mortars: From controversy to battlefield success

The LMP-2017 mortars were delivered to the Polish Army under a contract dated December 12, 2018, for the supply of 780 units to the Territorial Defence Forces. Once surrounded by controversy, this weapon has proven to be highly effective, notably during the defense of Avdiivka by the Ukrainians.

The LMP-2017 mortars are a modern, lightweight, and easy-to-use design developed by Zakłady Mechaniczne Tarnów (ZMT). Besides the Polish Army, they are used by Ukrainians, who praised them during the defense of Avdiivka. The pace of mortar development was rapid, highlighted by a ZMT representative who requested anonymity in a comment for WP Tech.

The catalyst for such rapid development was the long-standing presence of the Czech mortar, LRM vz. 99 ANTOS, in the Polish Army. The weapon was offered by the company Works 11, which was involved in a corruption case in the GROM Military Unit in 2019. ZMT seized the opportunity to replace the Czech mortars in 2017 after the order for ANTOS mortars for the Territorial Defence Forces was canceled.

Subsequently, the Czechs sued ZMT, claiming that the LMP-2017 mortar was a copy of the ANTOS, but they lost the case before the European Union Intellectual Property Office (EUIPO).

In 2023, based on a notification from Polish People's Party MP Jacek Tomczak, a proceeding began in the Warsaw District Prosecutor's Office regarding the alleged purchase of mortars by the Territorial Defence Forces that did not meet NATO standards.

The matter is, however, more complex. The LMP-2017 mortar is a modular design intended to use both Polish 59.4 mm ammunition and NATO 60 mm ammunition through a conversion involving the replacement of the barrel and a few other components.

A WP Tech source noted, "After the completion of development work and a positive outcome of factory tests, lightweight infantry mortar systems LMP-2017 were presented to the Ministry of National Defence (MON) in two versions. Ultimately, in 2018, the ministry decided to purchase a batch of 780 LMP-2017 mortars adapted to fire ammunition from a domestic manufacturer with a calibre of 59.4 mm, introduced into the armament of the Polish Armed Forces. However, ZMT maintains the design, technological, and production readiness to adapt the LMP-2017 mortars to any ammunition indicated by the MON, both from domestic and foreign manufacturers," the ZMT representative stated.

This configuration allows the Territorial Defence Forces to currently use large stockpiles of 59.4 mm ammunition and easily switch to NATO 60 mm ammunition once the appropriate conversion kits are acquired.

As the war in Ukraine shows, in the event of a full-scale conflict, the consumption of artillery and mortar ammunition can reach several thousand rounds per day. Utilizing older ammunition stocks (the stock levels are classified but could be several hundred thousand or even a few million rounds) in a modern system with the same ergonomics for using new NATO ammunition is a significant advantage.

The LMP-2017 mortar, whose name stands for "Light Infantry Mortar 2017," is a 60 mm design weighing less than 17 pounds. While just one soldier can operate the weapon, the optimal operation involves two people.

The mortar's design heavily utilizes polymers and light alloys wherever possible without compromising durability. ZMT emphasizes that its service life is 1,500 rounds, and it can fire up to 30 consecutive rounds.

The mortar's range is 0.7 miles for LM60 rounds and 0.8 miles for LM60N rounds. The weapon delivered to the Territorial Defence Forces is one of the newest lightweight mortar systems in the world, currently proving its effectiveness in Ukraine.

The LMP-2017 also serves as the basis for the export-offered LMC mortar, tested with Chinese ammunition used in the PP89 mortar and Swedish MAPAM ammunition (SAAB). This indicates that the manufacturer is trying to sell this weapon to countries in Southeast Asia, which had previously purchased weapons from Tarnów.

The 60 mm MAPAM round, which weighs 4 pounds, has a declared blast radius of 2,500 fragments, which is 131 feet from the point of impact, an impressive result for this class of ammunition.

The round is equipped with an advanced electro-pyrotechnic fuse that detonates about 5 feet above the ground, increasing the blast area and enabling it to hit soldiers hiding in trenches. The fuse contains a processor, battery, and radio signal emitter, so it "knows" its height and when to detonate.

However, it is worth noting that in accordance with the MIL-STD-1316D standard, the fuse arms itself only at a minimum height of 328 feet after leaving the barrel, when the mechanical safety shorts the electric circuit.