Historical Account
Translation from the Russian book "The Defense of the Fortress Osovets"
The Gas Attack of July 24th
On the 24th of July our troops at the Sosnenskaya theatre of operations (TO) were situated as follows:
The right flank of the Sosnenskaya to by the village of Belogrondy was occupied by three squadrons (the 1st squadron of the Zemlyansky regiment and 2 squadrons of militia men). Their task was to cover the first – the main – area of the Sosnenkaya TO from the right and cover the Zarechny fort from the north side using the second road leading to the Zarechny fort via the Budnensky bridge.
The centre of the Sosnenskaya TO and the left flank between the Rudsky channel and the Sosnya village were occupied by 1.5 battalions (including 1 battalion of the Zemlyansky regiment and 2 squadrons of militia men), situated in the following manner:
The first area of the Sosnenskaya TO along the railroad, as well as the Leonovo community, was occupied by one squadron (number 10); they had a partial support from half a squadron of militia men. These troops covered a most important way along the railroad and the Rudsky channel towards the Zarechny fort.
The second area was occupied by one squadron (number 9) which was also supported by half a squadron of militia men.
The third and fourth areas were also occupied by one squadron each (the 12 th and 11th squadrons of the Zemlyansky regiment). One squadron of militia men was situated by the forest ranger’s house, in reserve of the Sosnenskaya TO.
In view of this, the whole of the Sosnenskaya TO up to the village of Belogrondy was occupied only by nine squadrons (three of them consisting of militia men).
In order to strengthen the reserves of the Sosnenskaya TO, same as every day during this period of defence, one more battalion of the Zemlyansky regiment was sent from the Zarechny fort on the night from the 23rd to the 24th, however, just before dawn, around 3 AM, this battalion returned to the Zarechny fort as usual to rest after their night watch. Due to the small numbers of the garrison, it was not possible to leave a lot of troops at the Sosnenskaya TO.
Against our 1.5 battalions the Germans brought about 12 battalions of the 11th Landwehr division and besides that, according to the accounts of captives, about 6 battalions were kept in reserve.
Against the village of Belogrondy the Germans sent the 5th Landwehr regiment together with the 41st ersatz-reserve battalion. Their task, it seems, was to break through our defence in Belogrondy and furthermore to take over the Zarechny fort from the north side.
Against the first and second areas the Germans sent the 18th Landwehr regiment together with the 147th ersatz-reserve battalion whose mission was to break through the center of the Sosnenskaya TO cutting off the left flank troops and making them retreat to the marshes, as well as attacking the Zarechnaya TO via the Rudsky bridge.
The 76th Landwehr regiment was tasked with taking over the village of Sosnya and then advancing towards the forest ranger’s house in order to act against the left flank troops of the Sosnenskaya TO. These infantry troops were strengthened by the 1st combat engineer battalion and parts of the 36th combat engineer battalion.
The 75th Landwehr regiment was advancing along the railroad staying in reserve. Apart from the 14 battalions listed above, according to the words of captives 2 more regiments (numbers unknown) were also in the reserve of the attackers.
During recent preparations for an attack, over 30 gas batteries (several thousands of gas cylinders) were delivered and installed in 4 places in front of the enemy trenches, 6-7 batteries per installment. According to the captives, the batteries had been stealthily installed approximately 13 days before the attack and during this period of time the enemy was waiting for the most convenient atmospheric conditions in order for the poison gas to be at its most devastating.
The Release of the Gas and Its Impact
At 4 AM on the 24th of July the gas was released. It was of a dark green colour. The exact recipe of it, having chlorine in its base, was hard to determine, however, there was undoubtedly some other addition that intensified the choking effect.
The dense cloud of gas reached our trenches after only 5-10 minutes. It was heading towards the fortress fast, having a high starting speed and expanding to the sides (its initial size was no more than 2 versts [a verst = 1.0668 kilometres]) and up.
The impact of the gas cloud was such that, on the one hand, it created a cover hiding the movements of the enemy, and on the other hand, it brought lethal poisoning to everything it touched. The first victims of the poisoned fumes were scout parties and secret sentries who all died.
Despite the measures taken, such as burning tow and hay in front of the trenches, pouring and spraying of lime white and wearing respirators, almost all defenders of the 1st , the 2nd , the 4th and half of the 3rd area of the Sosnenskaya TO were poisoned by the choking gas to death.
Half of the people in the reserve of the Sosnenskaya TO were also poisoned. The expansion of the gas forward measured almost 20 versts, with the height of the cloud being 5-6 sazhen [a sazhen = 2.1336 m], but the devastating impact of the gas was notable up to 12 versts after which its influence weakened greatly.
Along with the lethal assault on our front troops, the poison of the gas also overwhelmed the majority of the defenders of the fortress, getting into even tightly closed rooms. All flora overmore than 12 versts was burned by the gas.
The garrison took all of the recommended measures against the gas but it turned out that theanti-gas masks available at the time only helped against the gas very little due to the small size of their neutralizing area and possibly due to the fact that using them in combat was incredibly difficult as it was hard to tie them on and keep them fitted tight to the skin; it was especially a challenge for the officers who, while commanding the soldiers, had to take the masks off or lift them up temporarily.
The strength of the gas was partly diminished by the conditions of the climate and local geography: the morning of the 24th was cold, foggy and damp, and after having passed over the wet marshes, the river and the moats the gas was considerably weakened which saved the garrison from enormous losses.
The Actions of the Attacking Parties
After the release of the gas, the enemy instantly sent up red flares everywhere, signaling that the gas had been released and the movement of the troops for frontal assault could now begin.
After the flares all German batteries opened heavy fire equally at all areas of the Sosnenskaya TO, especially at the village of Osovetsq seeing as the Germans were afraid of us attacking the advancing enemy flanks from there; the fire also covered the only road leading from the reserve of the Sosnenskaya TO via the Rudsky channel to the Zarechny fort which was the only place capable of sending reinforcements to Sosnya, and lastly they fired at the Zarechny fort, the Zarechnaya TO, the other forts and the base area, and meanwhile the artillery shells were also filled with a concoction that, at the explosion of the shells, created clouds of choking gas.
Under the cover of the artillery fire and choking gas the infantry started their assault. The attackers’ plan was of two parts: the first one – sending scouts ahead to investigate the impact of the gas on the defenders of the trenches, and the second one – storming the TO.
The scouts were assigned, numbering 200 people from each regiment, and the main attacking forces moved in two lines, keeping their ranks closed and having the reserves behind them.
At first the Germans attacked the first area of the Sosnenskaya TO which they were the closest to before July 24th; besides, a frontal attack may have been more difficult for the Germans but in case of success they would have cut off the centre and the left flank of the Sosnenskaya TO while pushing the troops occupying those areas out into the marshes and separating the Sosnenskaya and Belogrondskaya TOs.
By this time in the first area only two soldiers with machine guns were left alive. They wanted to open fire at the advancing Germans but were so weakened by the gas that they were not able to do it; then they dismantled the machine guns and buried the parts right there in the sand nearby and they themselves died right there, in the machine-gun nest.
Having quickly cut about 10 passages through the three lines of wire fences in front of the first area, the Germans flooded the area and went further on both sides of the railroad. The extremely heavy fire opened at that moment by our artillery made most of the Germans scatter and only some parts of the 18th Landwehr regiment broke through and reached the trenches of the reserves of the Sosnenskaya TO.
Continuing the frontal assault, they managed to reach the second area where the majority of defenders had also succumbed to the gas. From there a part of their forces made their way to the flank of the third area and another part continued advancing towards the reserves.
At the same time the 76th Landwehr regiment, having gathered in the forest to the west and south-west of the village of Sosnya and having lost approximately a thousand of their people to their own gas which had crept towards the west as they approached the fortress, attacked the village of Sosnya where very few remained alive by then. After crushing the skulls of 36 dead men, a part of the enemy forces moved from there towards the flank and the rear of the third area.
In the meantime one of the fortress machine gunners took his machine gun with him, moved away from the village of Sosnya and, having situated himself between the village of Sosnya and the third area, began shooting the Germans surrounding him at point-blank range. He managed to spend 2 ammunition belts but when he was inserting the third one into the gun, the Germans used the break, attacked him and tore him to pieces; only his forehead was left intact.
After that the Germans moved to the third area, surrounded it and attacked it from three sides but could not take it because the defenders continued to fight them off stubbornly with rifle and machine gun fire.
At that time the Germans who had been advancing from the first and the second areas reached the trenches of the reserve and started climbing the wire fences. Their advancement had cut off Belogrondy as they had passed the spot with the only bridge connecting the Belogrondskaya TO with the Sosnenskaya one and the rest of the fortress.
Due to the fact that the wire net only covered half the distance between the railroad and the Rudsky channel, some separate German parties started going around in order to attack the reserve from behind as they could not succeed from the front.
As a result, out of the whole front of the Sosnenskaya TO we only had the third area left with us; it separated the Germans operating to the left and to the right of it. The Germans advancing along the railroad were in a hurry to increase their success and separated into several lines which followed one another and couldn’t support each other in case we counterattacked.
The leading troops attacked the position of the reserve while the last troops were still near the Leonovo community which they were adapting for their own defence.
The leader of the Sosnenskaya TO captain Potapov, seeing the critical situation his people were in, ordered the militia men squadron that was in reserve to move forward and take over the rear trenches on the hill.
Thanks to this order the enemy was stalled; in the meantime the captain asked for reinforcements from the head of the 2nd defense department.
At the time when at the Sosnenskaya TO the enemy, meeting almost no resistance from the poisoned defenders of the 1st, 2nd and 4th areas of the Sosnenskaya TO, took those areas and closed in on the reserve, at the Belogrondskaya TO the Germans, counting about 2 squadrons, followed the gas and attacked the village of Belogrondy from north-west where by that time the area of approximately 2 versts only contained about 20 survivors with 2 machine guns one of which was operated by the warrant officer Retyunsky of the Zemlyansky regiment and the other one by a machine gunner of the fortress artillery force.
The Germans managed to cut down one row of the wire fence pickets within 50 seconds but were driven away by the machine gun fire. After that they regrouped twice for an attack but were scattered by the machine gun and artillery fire, and also their further advancement in the section between the villages of Osovets and Belogrondy was likely partially stalled by the appearance in their flank and rear of the scouts of the Livensky regiment that had been sent from the Budnenskaya TO to find out the situation at the Sosnenskaya TO.
Due to this critical situation which the garrison of the Sosnenskaya TO was in, and also realizing that the current state of affairs was a direct threat to the Zarechny fort and the Zarechnaya TO–as the Germans only had to defeat the reserve before storming the fortress–the fortress artillery was ordered to create a curtain of fire in front of the Sosnenskaya TO and the head of the 2 nd defense department, colonel Kataev, was ordered to counterattack with the available units of the Zemlyansky regiment.
The fortress artillerists, poisoned by the gas, could not start firing right away which was why the point units and the first line of the enemy got through the front of the Sosnenskaya TO and stabbed the remaining defenders, seizing the anti-assault weapons and machine guns, but the curtain of fire from the fortress artillery forces cut the enemy’s reserves from the first line, stopped their assault and drove them back with big losses.
The head of the 2nd defense department ordered the 13th squadron to move from the Zarechny fort to the Sosnenskaya TO, halt the Germans’ advancement towards the fortress at any cost and gain back the lost 1st area of the Sosnenskaya TO.
The 14th and the 8th squadrons were sent after them with the following orders: firstly to take back the village of Sosnya and secondly to take back the 2 nd area of the Sosnenskaya TO.
The 13th squadron which was the garrison of the Zarechny fort had already lost 20 men to poison gas; the commander of the squadron sub-lieutenant Kotlinsky was also poisoned but remained in the ranks. Combat-engineer officer sub-lieutenant Strzheminsky volunteered to be deployed with this squadron in order to ascertain during the fight what fortification constructions would be necessary within the Sosnenskaya TO.
The squadron, already strongly poisoned by the choking gas, crossed the bridge and the one-verst-long log way under heavy artillery fire from the enemy, formed a line and started an attack along the railway.
Having stepped out onto the reserve echelon line, sub-lieutenant Kotlinsky personally conducted reconnaissance and, assessing the situation correctly, led his squadron into a swift attack from 500 paces toward the advancing German lines.
The Germans opened heavy rifle and machine gun fire at the 13 th squadron and it didn’t stop the charge despite the fact the sub-lieutenant Kotlinsky was at this moment lethally wounded and gave the command of the squadron to combat-engineer officer sub-lieutenant Strzheminsky.
The latter unsheathed his sword and with a yell of “Hurrah!” charged at the Germans, leading the squadron.
The terrain of the attack was difficult: the ruins of old blindages were holes in the ground which people fell in; planks and logs stuck out everywhere, etc., but the brave squadron, truly worthy of their late commander, finished their swift attack and, using their bayonets, forced the Germans to abandon their positions and then also the front trenches of the 1st and 2nd areas of the Sosnenskaya TO; in the meanwhile 14 prisoners were captured.
Our anti-assault weapons and machine guns that were in the trenches and had been previously taken by the Germans were won back from the enemy in good condition. Sub-lieutenant Strzheminsky was suffering from acute poisoning from the choking gas but remained in the ranks.
After retaking the 1st and 2nd areas of the Sosnenskaya TO and finding out that the village of Belogrondy was now ours, the attack at the Leonovo community began.
The terrain made the attack difficult. Our own wide wire fences were blocking the way. Attacking was only possible along the line of communication whose length was fired at by the Germans from the trench between the 2 nearest wire fences. We had to employ the French method of trench warfare with hand grenades and move forward using gun shields.
The fortress artillery focused their fire on the Leonovo community and their efforts went beyond all expectations. The square plot of land, 50 paces in size, was bombarded from 9 heavy batteries and 2 light ones, and also our troops opened fire at the enemy’s rear from the Belogrondskaya TO and the first area.
As a result, the Germans were mostly killed, with only a few of them having had time to retreat, and there was even no need to attack with bayonets, and that was how by 10 AM we had taken over the last and most important bastion of the Germans.
At the time when at the first area there was fighting to retake the first area and the second one, as well the Leonovo community, and when the gas started to disperse, the head of the 3rd area, the commander of the 12th squadron sub-lieutenant Cheglokov, having found out that the Germans were separated into 2 forces by his area and that one of those forces had taken over he village of Sosnya and was determined to overwhelm the 3rd area from the flank and the rear, immediately moved a platoon to the flank and opened heavy rifle and machine gun fire at the Germans in order to prevent their takeover.
Despite attacking fiercely, the Germans were defeated twice and had to retreat to the village of Sosnya where, hiding in the folds of the terrains and in the tall rye, they continued to shoot.
At this moment the 14 th squadron which had been sent to support the left flank of the Sosnenskaya TO arrived. Sub-lieutenant Cheglokov together with his people and half the 14th squadron assumed the offensive energetically and, despite the Germans’ strong resistance, he personally led the troops into a bayonet attack which forced the Germans out of the trenches of the village of Sosnya (the 4 th area) which he completely took over, returning our previously captured cannons and machine guns and also taking 14 prisoners.
The 8th squadron which had been sent out after the 14th squadron reinforced the second area of the Sosnenskaya TO and helped to keep it. In this way, by 11 AM, that is, after 7 hours, the famous gas attack was finished and it was brilliantly and selflessly resisted by parts of the glorious Zemlyansky regiment.
All direct commanders of the fortress, officers and soldiers of the Zemlyansky regiment and the fortress artillery forces, poisoned by the gas in their majority, displayed heroism, selflessness and resourcefulness.
The tiniest delay in sending the squadron out for a counterattack, any tardiness in firing by the fortress artillery – they could all have led not only to losing the Sosnenskaya TO but also to the Germans taking over the Zarechnaya TO and the Zarechny fort the loss of which to the enemy would inevitably result in the fall of the fortress.
The captured Germans taken during the gas attack said that every attacker from the highest commanders to the last private of the German division had been certain that this time the garrison could not be saved, that nothing could withstand the power of the gaseous poison.
The certainty that the whole garrison would perish from the gas had been so great that the Germans had assigned several squadrons in advance for burying the dead, and all carts had been prepared and ready to enter Osovets. For that reason the first shot and then the increasing fire from the fortress artillery was extremely astonishing and therefore it was possible to understand all the atrocities that the conniving enemy carried out against the honoured heroes who died for the precious stronghold.
The enemy’s new unsuccessful attempt to take the fortress via a gas attack did not discourage further efforts and, while continuing their blanketing fire, they, according to the words of the Polish soldiers who had defected to the fortress, started to prepare the second, an even more lethal gas attack; but this second attack was late thanks to the fortress evacuation that followed.
All in all, this gas attack was the end of the military operations by the fortress. Although the Germans continued firing at the fortress, it was no longer as intense as previously. During this period of firing, scout parties from both sides went out to explore and some skirmishes occurred between small squads.
On the 4th of August the fourth and the last period of the siege and defense of the fortress was over.
German Empire 
Russian Empire 
