But before going into detail on the specifics of the first iteration, it is insightful to consider the conversion of the first battle fortress. Of little use to the Islamic State in its original role, the BTS-5B was heavily modified through the addition of an armoured cabin over its original body. For this purpose, the crane, the snorkel and various crates containing additional tools were removed. The dozer blade and winch were retained however.Armament consists of a shielded pintle-mounted 12.7mm DShK heavy machine gun and several mounts for light-machine guns. The occupants also made use of M16s and AKMs to complement the single DShK during the vehicle's first and only use on the battlefield.Large blocks presumably filled with sand concrete were installed on top of the newly erected platform to act as armour plating while large rubber side skirts were fitted to either side of the battle fortress. Combined, they provided the occupants with protection against small-arms fire, explosive fragments and perhaps the occasional rocket propelled grenade (RPG) from the front and sides.As a result of the blockage of the driver's hatch by the support beams of the platform, the driver had to enter his position by a hatch on the floor of the platform. The support beams also blocked the driver's viewing port, forcing the driver to stick his head out while maneuvering the vehicle. Armoured glass was installed to make up for this increase of vulnerability however.All in all, the conversion was an impressive project which must have cost the Islamic State a large amount of man hours to accomplish, which is also why its poor battlefield career comes as somewhat as a surprise.The battle fortress could have been put to good use in urban environments, where the vehicle would have been used as a heavily armoured battering ram capable of providing fire support to advancing troops. Its flexible, albeit light, armament would have been ideally suited for targeting elevated areas such as higher floors of flats, with its armour warding off most retaliatory fire.Instead, the fighters of the Islamic State used the battle bus on the open plains near Shekhan , Nineveh Governorate, where the Islamic State waged an offensive against entrenched Peshmerga forces on the 25th of January 2015. Footage of the failed offensive can be watched here Shekhan was the site of a series of heavy attacks by the fighters of the Islamic State. The typical pattern of such an attack would include one vehicle-borne improvised explosive device (VBIED) followed by an attack with captured U.S. M-1114s, Badger ILAVs or M1117 ASVs. As Peshmerga forces held the high-ground, and saw the vehicles coming from miles away, the exact logic behind these attacks remains unclear, especially after MILAN ATGMs reached the Peshmerga forces.During the attack on Shekhan, several (up-armoured) M-1114s, one up-armoured Badger ILAV, one M1117 ASV and the battle fortress moved up to Peshmerga positions, but quickly came under under heavy machine gun, mortar, and tank fire from the high ground. Most of these rounds either missed or ricocheted from the vehicles' additional DIY armour. As a result, several vehicles managed to advance close to the mountain before being taken out.The battle fortress on the other hand got stuck in a ditch, was hit by an RPG and probably also a mortar round, killing its exposed crew and ending the career of the first mobile battle fortress.The first iteration made its first and only appearance in the Islamic State propaganda video 'The Dabiq Appointment' , which covered an exercise of an IS armoured formation in Wilayat Ninawa (Nineveh Governorate) in Mosul, Iraq. The 'Dabiq Appointment' refers to the town of Dabiq in Northern Syria, where according to the Islamic State, the final battle between righteousness (Islamic State) and wrongness (everything not the Islamic State) will take place.Contrary to what one might expect, a large scale deployment of Coalition forces near this town and a resulting battle is what the Islamic State desperately wanted. It is thé way the Islamic State wants to confront the 'Crusaders' (the Coalition), referring to its air attacks and drone strikes as acts of cowardness. Nonetheless, the small town was quietly captured by Turkish-backed Free Syrian Army forces from Islamic State in October 2016. To further add to its threat, the video also includes a shot of an Islamic State tank marching on the Colosseum in Rome, Italy.Featuring in the 'Dabiq Appointment' is the 3rd al-Farouq armoured brigade, which together with the 'Shield Battalion' and 'Storming Battalion' is responsible for operating most armoured fighting vehicles (AFVs) in Wilayat Ninawa. The 3rd al-Farouq armoured brigade is seen training for the ''imminent'' battle at Dabiq, shooting up targets and storming positions while employing a host of armoured fighting vehicles including 2 T-55s, 1 Type-59, 2 MT-LBs, 2 Badger ILAVs MRAPs, 1 battle fortress and 1 BTR-80UP in junction with well-equipped infantry.The image below shows the seal of 3rd al-Farouq Armoured Brigade, reading: ولاية نينوى - الجند (?) لواء الفاروق المدرع الثالث - 'Wilayat Ninawa - Soldiers (?) - al-Farouq Armoured Brigade - 3rd'. The second part of the Shahada: محمد رسول الله - 'Muhammed is Allah's prophet' is seen on the right. This is sometimes seen on Islamic State operated vehicles and is believed to be applied for decorative purposes only.As with its predecessor, this BTS-5B was heavily modified for its new role as an armoured fighting vehicle. The crane, snorkel and various crates normally mounted on top of the vehicle were removed. Although unlikely to ever see use, the dozer blade was retained however. To compensate for the removed headlights, the light beams of which would have been blocked by the slat armour, two new headlights have been installed on the front mudguards.While the previous version had to do with simple blocks of armour installed around its newly erected platform, the new vehicle comes with slat armour installed around the hull and around its raised platform. Although certainly impressive by its looks, the strength of the protective slat armour and the firmness of its supportive mounts look marginal at best, and the driver's view is likely seriously hampered by the slat armour installed in front of him. No rubber side skirts are seen mounted this time, which was however a feature of the first battle fortress.Armament has been much improved from the previous version, which only donned a single 12.7mm DShK in addition to several mounts for light-machine guns. The new battle fortress comes with the same 12.7mm DShK, this time mounted on the commander's cupola, and a 14.5mm KPV in an armoured cupola taken from an ex-Iraqi Army M-1114 placed on top of the raised platform. While providing an easy target for the enemy, the elevated position of the 14.5mm KPV offers it a great view of its surroundings, and enables it to fire at practically any target with a Line Of Sight (LOS) to the vehicle.Contrary to the previous version, which was more of a heavily armoured battering ram carrying infantry than it was a real AFV, this vehicle is much more akin to a true armoured fighting vehicle. The sheer size of the erected platform serves both as an advantage as well as an disadvantage as it makes the vehicle an ideal target for ATGMs and RPGs.While the eventual fate of the second battle fortress remains unknown, the vehicle could just as well have been sent off against Peshermerga positions around Mosul. Indeed, both vehicles might serve as a testimony to the fact that although the fighters of the Islamic State were often quick to adapt to most combat situations, comprehension of suitable tactics regarding the operation of armoured fighting vehicles remained beyond the Islamic State fighters' grasp in this region.