Question: During the battle of Moscow what prevented the Germans from reaching Tula until October 1941?
About the article "Battle of Moscow", section "Mozhaisk defense line (13 – 30 October)".

Candidate passages:
German war crimes during the Battle of Moscow In the village of Ershovo in Moscow Oblast 100 Soviet civilians and captured soldiers were blown up in the village's church.
In the village of Vysoko Germans burned 70 civilians alive and 20 captured Soviet soldiers.
In the village of Dubna Germans hanged 42 civilians, in Prudnaja they burned 20 civilians alive and shot 50 civilians in the village of Kolodeznaja (Tula Oblast).
In the village of Slobodino of Moscow Oblast Germans raped and killed 15 Soviet women.
In the village of Boljshoe in Tula Oblast, Germans burned 56 civilians and wounded Soviet soldiers alive.
In the village of Chornaja Grjazj in Moscow Oblast 30 civilians were shot and their bodies were hanged along the way.
Two women were also raped and killed: Soloninkowa E. and Erohina K. During the retreat from Worjushino in Kalinin Oblast Germans shot 26 civilians (10 among them were children).
On December 20, 1941 in Volokolamsk, Germans burned 600 wounded Soviet soldiers alive. 
Tula, a historical Russian city with important military industry South of Moscow, became the target of a German offensive to break Soviet resistance in the Moscow area between 24 October and 5 December 1941.
The heavily fortified city held out, however, and secured the Southern flank during the Soviet defence of Moscow and the subsequent counter-offensive.
Tula was awarded the title Hero City in 1976. 
Mozhaisk defense line (13 – 30 October).
By 13 October 1941, the "Wehrmacht" had reached the Mozhaisk defense line, a hastily constructed double set of fortifications protecting Moscow's western approaches that extended from Kalinin towards Volokolamsk and Kaluga.
Despite recent reinforcements, only around 90,000 Soviet soldiers manned this line - far too few to stem the German advance.
Given the limited resources available, Zhukov decided to concentrate his forces at four critical points: the 16th Army under Lieutenant General Rokossovsky guarded Volokolamsk, Mozhaisk was defended by 5th Army under Major General Govorov, the 43rd Army of Major General Golubev defended Maloyaroslavets, and the 49th Army under Lieutenant General Zakharkin protected Kaluga.
The entire Soviet Western Front—almost completely destroyed after its encirclement near Vyazma—was being recreated almost from scratch.
Moscow itself was also hastily fortified.
According to Zhukov, 250,000 women and teenagers worked building trenches and anti-tank moats around Moscow, moving almost three million cubic meters of earth with no mechanical help.
Moscow's factories were hastily converted to military tasks: one automobile factory was turned into a submachine gun armory, a clock factory manufactured mine detonators, the chocolate factory shifted to food production for the front, and automobile repair stations worked fixing damaged tanks and military vehicles.
Despite these preparations, the capital was seemingly within striking distance of German "panzers" and was targeted in massive air raids, although these raids caused only limited damage because of extensive anti-aircraft defenses and effective civilian fire brigades.
On 13 October 1941 (15 October 1941, according to other sources), the "Wehrmacht" resumed its offensive.
At first, the Germans attempted to bypass Russian defenses by pushing northeast towards the weakly protected city of Kalinin, and south towards Kaluga and Tula, capturing all except Tula by 14 October.
Encouraged by these initial successes, the Germans launched a frontal assault against the fortified line, taking Mozhaisk and Maloyaroslavets on 18 October, Naro-Fominsk on 21 October, and Volokolamsk on 27 October after intense fighting.
Because of the increasing danger of flanking attacks, Zhukov was forced to fall back, withdrawing his forces east of the Nara River.
In the south, the Second Panzer Army initially advanced towards Tula with relative ease because the Mozhaisk defense line did not extend that far south and no significant concentrations of Soviet troops blocked their advance.
However bad weather, fuel problems, and damaged roads and bridges eventually slowed the Germans, and Guderian did not reach the outskirts of Tula until 26 October 1941.
The German plan initially called for a rapid capture of Tula followed by a pincer move around Moscow.
The first attack, however, was repelled by the 50th Army and civilian volunteers on October 29 after a desperate fight that occurred within sight of the city.
On 31 October, the "OKH" ordered a halt to all offensive operations until increasingly severe logistical problems were resolved and the "rasputitsa" subsided.
The 75th Cavalry Division was a cavalry formation of the Red Army during the Great Patriotic War.
It was formed in September and October 1941 in Novosibirsk, Siberian Military District.
The compound was formed as part of the ruling NKO USSR № 459ss on 11 August 1941.
The redeployment of the division of the Soviet-German front was launched in November 1941. передислоцирована из Колышлея в район станция Ласково, Солодча.
In accordance with Directive Stavka № 4299 from 2 November 1941 it was relocated from Novosibirsk to Glotovku ; directive Stavka on 24 November 1941 relocated from Kolyshleya station area affectionately Solodcha.
The division was part of the 'operational army' (part of the front-line fighting force) from 5 December 1941.
During the war the division was always acted on the Western front and took part in the offensive phase of the Battle of Moscow.
As part of the 10th Army participated in the Tula offensive (6–17 December 1941).
It was subordinated to the 10th Army from 6 December 1941 to 19 December 1941.
The division along with the 41st, 57th Cavalry Divisions to Mishulin's Cavalry Group as the mobile group for the 10th Army.
The group minus the 41st Cavalry Division was assigned to attack the flank of the German 2nd Panzer Army south of Tula.
Before the group was fully committed the group was assigned to the 1st Guards Cavalry Corps.
It was then transferred to the 1st Guards Cavalry Corps of the Western Front - January 1942 to 21 March 1942.
Then the division participated in one of the greatest cavalry raids of the war.
On the night of 26–27 January 1942 the Corps slipped across the lines into the German 4th Army's rear areas and began what would be a six month operation against the German supply lines.
The division was dissolved on 26 March 1942, and portions were used to replenish the 2nd Guards Cavalry Division. 
Tula was first mentioned in the Nikon Chronicle in relation to a military operation conducted in 1146.
As the chronicle was written in the 16th century, the date is disputed.
The first confirmed mention of Tula dates to 1382.
In the Middle Ages, Tula was a minor fortress at the border of the Principality of Ryazan.
As soon as it passed to the Grand Duchy of Moscow, a brick citadel, or kremlin, was constructed in 1514–1521.
It was a key fortress of the Great Abatis Belt and successfully resisted a siege by the Tatars in 1552.
In 1607, Ivan Bolotnikov and his supporters seized the citadel and withstood a four-months siege by the Tsar's army.
In the 18th century, some parts of the kremlin walls were demolished.
Despite its archaic appearance, the five-domed Assumption Cathedral in the kremlin was built as late as 1764.
In 1712, Tula was visited by Peter the Great, who commissioned the Demidov blacksmiths to build the first armament factory in Russia.
Several decades later, Tula was turned by the Demidovs into the greatest ironworking center of Eastern Europe.
The oldest museum in the city, showcasing the history of weapons, was inaugurated by the Demidovs in 1724, and Nicholas-Zaretsky Church in the city houses their family vault.
The first factory to produce samovars industrially was also established there in the course of the 18th century.
After the Demidovs moved the center of their manufacture to the Urals, Tula continued as a center of heavy industry, particularly in the manufacture of matériel.
In the 1890s, Ivan Savelyev, a medical orderly, became the founder of Social Democracy in Tula, and set up a workers' study circleThe city grew rapidly in the early 20th century as a result of arms production during the 1905 Russo-Japanese War and World War I. Tula's factories also manufactured weapons for the Red Army during the Russian Civil War of 1918–1921.
During the Great Patriotic War (World War II) of 1941–1945, the city was important in the production of armaments.
Tula became the target of a German offensive to break Soviet resistance in the Moscow area between October 24 and December 5, 1941.
The heavily fortified city held out, however, and Guderian's Second Panzer Army was stopped near Tula.
The city secured the southern flank during the Battle of Moscow and the subsequent counter-offensive.
Tula was awarded the title Hero City in 1976.
It is home to the Klokovo air base and the Tula Arms Plant.