Forte Tombion

Forte Tombion: Remains of the casemate housing

Forte Tombion is a former Italian fortification in the northern Italian province of Vicenza . It was built between 1884 and 1885 on the road leading through the Brenta Gorge about two kilometers north of Cismon del Grappa .

location

The barrier is located at a narrow point of the Canale di Brenta , as the southern continuation of the Valsugana valley from Primolano is called, about 24 kilometers north of Bassano del Grappa . The river Brenta, which flows through the valley, forms a loop to the west at this 200 m wide gorge, where the barrier was built. Since the third Italian War of Independence in 1866, the border between the Kingdom of Italy and the Empire of Austria , from 1867 the Austro-Hungarian Monarchy , was only a few kilometers north of Primolano, a district of Cismon del Grappa on the northern edge of the Canale di Brenta.

Building history

The strategic importance of the Valsugana valley as a gateway to the north and south was known since ancient times, but the narrow point of this valley between Primolano and Cismon del Grappa was ideal for the construction of a defensive system. A castle built within sight of Forte Tombion, the Covolo di Butistione, was first mentioned by name as early as the 11th century.

After the annexation of Veneto to the Kingdom of Italy in 1866, the Italian General Staff worked out plans for the construction of barriers in the vicinity of Cismon del Grappa, Primolano and Arsiè relatively quickly . Ultimately, however, as in the neighboring Austro-Hungarian monarchy, there was a lack of the necessary financial resources to implement these plans.

Between 1875 and 1879, a commission set up to defend the Alps took on the task of drawing up a defense plan. The commission came to the decision in the early 1880s to build only one barrier in the area at the moment, with which several intrusion directions could be kept under control. The choice fell on one of the narrowest points in the Canale di Brenta between Primolano and Cismon del Grappa, which was known under the name “Tombion” and from which one could have worked both north and south in the event of a bypass. At that time, however, it was already known that an effective closure would only be promising by building further works in the area, which was the basic idea for the later construction of the Brenta-Cismon barrier.

In 1884, work began on Forte Tombio. The ground between the mountain wall and the river bank was leveled with the help of mine blasting. The first phase of construction was completed in 1885. In 1896, a few mine chambers were built in the area, with which the surrounding traffic routes, including the bridge leading south of the plant over the Torrente Cismon , could be blown up if necessary .

When in 1910 the construction of the last section of the Valsugana railway line between Bassano and Primolano at Forte Tombion, begun in 1908, was discussed, the problem arose as to how the railway line could be integrated into the facility without questioning the function of the barrier. The changes that followed did not only affect the structural inclusion of the railway line, but also the reinforcement, which was reduced and only oriented towards the north. In the period that followed, no further work was done on the Forte Tombion, as it was considered out of date and outdated after the construction of the more modern Leone and Lisser plants .

description

Sketch of the system made by the kuk Evidenzbureau

Forte Tombion consisted of two one-story casemate batteries , which were perpendicular to the valley road and facing north towards Primolano and south towards Cismon. Between the two batteries there was a two-story casemate for accommodation as well as a two-story building running parallel to the road on the eastern edge of the valley directly on the rock face, in which the service rooms , the armory and the powder room were located at the southern corner, while the officers' quarters were located on the upper floor. On the west side of the facility facing the Brenta River, a stone wall with loopholes bordered the barrier. Such an open infantry position had also been set up on the east side up the slope, facing south and north.

In front of both battery blocks there were two earth walls to protect the two casemate batteries. Between the earth walls there was a 6 meter wide and 5 meter deep trench. Two retractable bridges led across both trenches at the eastern end of the trench directly in front of the two gates of the facility, over which the valley road was led through the facility. The two gate passages were closed with iron gates that had loopholes and each of which had a small door for pedestrians to pass through.

The two casemate batteries each had 5 gun casemates, which were open at the rear for the smoke outlet. In addition, there were ammunition and standby casemates in the two battery blocks for the gun crews. On the roof of the battery blocks there were balustrades for the infantry from which the apron could be painted. The casemate housing only had windows and doors on its south side. Under the two retractable bridges was the moat , which could be reached via postern . Due to the winding valley, the range of the factory guns was 1,250 meters to the north and 4,000 meters to the south. With the in-factory yard in the open position mortars also the locks at Primolano could be under fire if they had been occupied by the enemy. The crew were 180 men plus another 180 men in the event of a defense.

During the renovations carried out in 1911, the Primolano-Bassano railway line was integrated into the defense system by leading it past the plant through an artificially bricked tunnel parallel to the road. On top of this, 3-meter-high stone parapets with rifle loopholes were erected, which seamlessly connected to the wall leading east up the slope. In the middle of the tunnel, a passage led to the aforementioned casemate with the service and guard rooms, which was parallel to the street. Both tunnel entrances could be closed with iron gates with loopholes.

Armament

After completion in 1885, the factory was armed as follows:

• ten 15 GRC / ret howitzers on sideways movable mounts , five of them facing north and five facing south with a total of 5,000 shells ;
• four 15 AR / ret mortars with 1,600 rounds of ammunition, they could be used both north and south;
• two rapid fire cannons 9 ARC for the trench blows.

In 1911 the armament was limited to:

• four cannons 75 A model 1906 with firing direction Primolano;
• two mortars 149 mm;
• four Gardner Mod. 1886 machine guns , which could be used on the north or south side as required.

War history

A few days after the start of the First World War and the subsequent Italian declaration of neutrality on August 3, 1914, the Brenta-Cismon lockdown command was officially launched on August 8, with the aim of achieving the full operational readiness of this border section and the as yet unfinished and partly to finish work on the barrier that has not yet started.

1915

On May 22, 1915, Forte Tombion was drafted into a state of defense, thus establishing full alert. At 8:30 p.m. on the same day, the arresting command in Arsiè ordered the mobilization and, the next day, full readiness for the Brenta-Cismon barrier in case of war. At that time the latter comprised the fortresses Forte Tombion, Tagliata Covolo di Sant'Antonio, Tagliata della Scala, Tagliata delle Fontanelle, Forte Cima Lan, Forte Leone, Forte Lisser, the cavern battery Forte Coldarco and seven other battery positions with a total of 28 guns of various calibers.

On May 24th at 1:00 a.m., the 15th Division in the Brenta Cismon area gave the order to attack, and the permanent fortifications there were supposed to support the advance of the troops with their factory artillery. This did not happen, however, because the Austro-Hungarian line of defense had been relocated from the imperial border to an easier-to-defend line Lagorai - Levico - plateau of Folgaria / Lavarone , and so the Valsugana was cleared so that the advancing Italian troops did not encounter any resistance and thus any support from the Brenta-Cismon blocking group became obsolete. A fortnight later, the foremost Italian line was at Ospedaletto , about 20 kilometers as the crow flies from Forte Tombion. Until the beginning of November 1915, Tombion retained the reinforcement established in 1911, even if the crew had been gradually reduced. At the end of November it formed, together with the Tagliata della Scala and Covolo di Sant'Antonio, the sub-group valley floor ( Gruppo opere fondovalle ) within the Brenta-Cismon barrier.

1916

The Austro-Hungarian South Tyrol offensive in the spring of 1916 initially only hit the restricted group marginally. As the offensive progressed, however, the Italian army command saw the danger of an Austrian break-in into the Canale di Brenta from the plateau of the seven municipalities . In order to counter the risk of bypassing, the relocation of the Forte Tombion factory artillery from the northern to the southern battery casemate was arranged on May 26, 1916. In addition, the ammunition supply was replenished and wire barriers were set up in the direction of Cismon. On May 27th, two batteries with 120G cannons for the artillery position on the Col del Gallo were additionally deployed to secure Forte Tombion's flank. After the offensive subsided and the threat of a possible descent into the Canale di Brenta ended, activities in Tombion also fell asleep again. In the period that followed, the barrier was used briefly as a prison for deserters and then only as a reserve store for troops and material, which also resulted in a further reduction in the occupation and armament. At the end of November 1916, after the front line had been strengthened, the Army Group Command decided to dissolve the Brenta-Cismon barrier, as all the facilities were far behind the front. Only the roadblocks retained a minimal function as road control points and were manned by Carabinieri . At the end of December 1916, Tombion was completely disarmed.

1917

On November 5, 1917, as a result of the German-Austrian breakthrough at Karfreit, the ordered retreat of the Italian troops of the XVIII. Army corps between the Valsugana and the eastern Lagorai on the new line Grappa - Piave , which connected between San Marino in the Canale di Brenta along the Grappa massif over 50 km to the Ponte della Priula on the Piave. The retreat was covered by a rear guard with the task of slowing down the advance of the Austro-Hungarian troops and rendering all fortresses and traffic routes in the area unusable or destroying them as much as possible. On November 12th, the Austrian associations finally reached the first works of the Brenta-Cismon, Leone and Cima di Lan barriers, the latter being blown up shortly before by the Italians. On the same day everything was ordered to prepare for the demolition of Forte Tombion and the two roadblocks Tagliata della Scala and Fontanelle. On November 13, the two roadblocks near Primolano were partially blown up one after the other. When the Tombion factory was also blown up, it turned out that some of the detonators had become damp. Before they could be exchanged, the demolition squad was caught under fire by an Austrian patrol of the 81st Austro-Hungarian Infantry Regiment , killing several men. During the hasty demolition that followed, only parts of the plant could be demolished, including parts of the casemates and the street passage. After the occupation by Austro-Hungarian troops and the clearing of the blasting debris , the facility, called Forte delle Piovega di Sotto by the Austrians , was used as an auxiliary area from December 1917.

Forte Tombion: After the 1918 explosion

1918

In 1918 the hinterland of the front around Forte Tombion, especially the railway line that was repaired by the Austrians, was repeatedly the target of Italian artillery attacks. During one of these attacks in the spring of 1918, a train loaded with ammunition standing in front of the southern tunnel exit was hit. Parts of the plant were also damaged in the devastating explosion. The factory gate in the direction of Cimon, which had already been damaged in the Italian blast in November 1917, including the two gate pillars, collapsed completely. After the retreat of the Austro-Hungarian troops as a result of the Italian offensive launched by Vittorio Veneto on October 24 , Forte Tombion fell back into Italian hands on November 3, 1918.

Post-war period and World War II

After the end of the First World War, Forte Tombion was abandoned by the Italian army and left to its fate. During the Second World War , the Todt Organization used it as an explosives storage facility from 1943 onwards. On the night of June 6th to 7th, 1944, Tombion was the target of a sabotage attack by the Italian Resistance . The order issued by the Special Operations Executive provided for the explosives stored in Tombion to be used to sabotage the railway line immediately next to it in order to disrupt the German supply routes, as the Germans switched the rail traffic partly from the Brenner line , which was heavily disrupted by Allied air raids, to the heavier one had laid the Valsugana Railway to be attacked. On June 7, 1944 at 1:00 a.m., the resistance group managed to blow up the railway tunnel next to Forte Tombion, which resulted in the complete interruption of rail and road traffic for five days. This action, known as the “Sabotage of the Tombion”, is considered to be one of the most important of the Italian resistance.

After the end of the Second World War, Forte Tombion finally lost all importance and was largely dismantled from the 1960s in the course of the expansion of the railway line and in particular the Strada Statale 47 della Valsugana . The remains of Forte Tombion are privately owned and can only be viewed from the outside.

photos

• 

  The southern casemate battery on the left, the casemate accommodation on the right

• 

  Accommodation casemate and on the right the remains of the northern casemate battery

• 

  Northern rifle gallery (with the niche of the retractable moat bridge almost filled in)

literature

• Luca Girotto: Forte Tombion. La sentinella del Canal di Brenta. Storia ed immagini per la visita alla più antica tra le opere permanenti della “Fortezza Brenta-Cismon”. Associazione Storico Culturale della Valsugana Orientale e del Tesino, Borgo Valsugana 2008, ISBN 978-88-903488-0-8 .

Web links

Commons : Forte Tombion  - collection of images, videos and audio files

Individual evidence

1. ↑ Luca Girotto: Forte Tombion. La Sentinella del Canal di Brenta. Storia ed immagini per la visita alla più antica tra le opere permanenti della “Fortezza Brenta-Cismon”. Pp. 21-23
2. ↑ Luca Girotto: Forte Tombion. La Sentinella del Canal di Brenta. Storia ed immagini per la visita alla più antica tra le opere permanenti della “Fortezza Brenta-Cismon”. Pp. 46-49
3. ↑ Luca Girotto: Forte Tombion. La Sentinella del Canal di Brenta. Storia ed immagini per la visita alla più antica tra le opere permanenti della “Fortezza Brenta-Cismon”. Pp. 31-33
4. ↑ Luca Girotto: Forte Tombion. La Sentinella del Canal di Brenta. Storia ed immagini per la visita alla più antica tra le opere permanenti della “Fortezza Brenta-Cismon”. Pp. 35-36
5. ↑ Luca Girotto: Forte Tombion. La Sentinella del Canal di Brenta. Storia ed immagini per la visita alla più antica tra le opere permanenti della “Fortezza Brenta-Cismon”. Pp. 46-48
6. ↑ Luca Girotto: Forte Tombion. La Sentinella del Canal di Brenta. Storia ed immagini per la visita alla più antica tra le opere permanenti della “Fortezza Brenta-Cismon”. Pp. 36-38
7. ↑ Luca Girotto: Forte Tombion. La Sentinella del Canal di Brenta. Storia ed immagini per la visita alla più antica tra le opere permanenti della “Fortezza Brenta-Cismon”. P. 50
8. ↑ Luca Girotto: Forte Tombion. La Sentinella del Canal di Brenta. Storia ed immagini per la visita alla più antica tra le opere permanenti della “Fortezza Brenta-Cismon”. Pp. 53-56
9. ↑ Luca Girotto: Forte Tombion. La Sentinella del Canal di Brenta. Storia ed immagini per la visita alla più antica tra le opere permanenti della “Fortezza Brenta-Cismon”. Pp. 58-62
10. ↑ Luca Girotto: Forte Tombion. La Sentinella del Canal di Brenta. Storia ed immagini per la visita alla più antica tra le opere permanenti della “Fortezza Brenta-Cismon”. Pp. 64-75
11. ↑ Luca Girotto: Forte Tombion. La Sentinella del Canal di Brenta. Storia ed immagini per la visita alla più antica tra le opere permanenti della “Fortezza Brenta-Cismon”. Pp. 80-88
12. ↑ Partisan Action Forte Tombion in Italian , accessed on May 11, 2017.

Coordinates: 45 ° 56 ′ 16.6 "  N , 11 ° 43 ′ 29.3"  E