Tama River gravel mining
Gravel extraction in the Tama River basin has been carried out since the Edo period, and the gravel was sold to the shogunate. luck money There are records of what happened. However, it was not until the mid-Meiji period that things got serious, and river gravel was being scraped up using joren. gravel winnow They were transported to Tokyo, sorted through metal sieves, and transported to Tokyo. This is a large drilling - This was before the introduction of sorting machines, and all gravel extraction was done by hand, giving rise to the term "Tama River gravel sieve." In addition, gravel collected in the downstream area is used to build wooden sails. gravel boat using Rokugo The cargo was transported to Tokyo, where it was transshipped and shipped throughout Tokyo. Around the Meiji period, river gravel was mostly used as ballast for roads and railways, and it seems that large-grained gravel was required. In villages along the Tama River, gravel sifting became a source of cash income for farmers.
Gravel mining after the Taisho period
In the Taisho era, concrete aggregate Gravel from the Tama River also came to be used. Especially after the Great Kanto Earthquake of 1923, reconstruction demand As a result, the production of river gravel will increase rapidly. At this time, the center of gravel mining on the Tama River was in the middle reaches from Tachikawa to Inagi. This is because the downstream area is already occupied. From around the end of the Taisho period, large excavators and mechanical ships began to be used, and the work from mining to sorting and cleaning of gravel began to be used. consistent Mechanization and rationalization of the gravel industry progressed.
gravel railway of Laying
Gravel extraction is carried out by railways. laying There was a deep relationship with both. The following is a list of railways built for the purpose of collecting and transporting gravel in the area around Inagi.
The Tamagawa Gravel Railway (later Nambu Line) was established in 1920 and opened between Kawasaki and Daimaru in 1927, and between Chofu and Tamagawara in 1916. Keio has started operations electric track (later Keio Line) Tamagawara Line , Tama Railway (later Seibu Tamagawa Line), which opened the Chuo Line from Musashisakai to Koremasa in 1922, and Tokyo Gravel Railway, which began operating between Kokubunji and Shimogawara in 1910. (Japan National Railways Shimogawara Line )And so on. Looking at when they were laid, all of them were constructed in just 20 years, from the end of the Meiji period to the beginning of the Showa period, and these railways were already completed in 1929. It will be. Looking at the location of the railways that have been built, the main lines are the Nambu Line, Keio Line, and Chuo Line, and from there fishhook shape to branch do branch line You can see that it extends towards the Tama River.
Effects of gravel mining
With the mechanization of gravel mining and the realization of mass transportation through the construction of railways, gravel mining from the Tama River reached its peak from the end of the Taisho era to the early Showa era. However, large quantities of gravel mining have various negative effects on the Tama River itself. seawall embankment destruction of, riverbed surface Agricultural water consumption due to decline in Water intake difficulties , water quality pollution These include negative impacts on fisheries. In order to cope with this, from 1930 onwards, Futako Bridge more upstream, Hinobashi In more downstream areas high water bed Mining is not permitted in low water bed It became only.
After the war, postwar reconstruction gradually progressed in the 1940s, and gravel mining in the Tama River returned to its prewar level. booming I started to get it back. but Random digging Gravel pollution also progressed, and in 1954, the Tama River Gravel Collection Control Agreement was concluded, tightening regulations on the Tama River downstream from Hino Bridge. In the 1950s, regulations were further tightened, and in 1960, Ome City's Manyenbashi Bridge Commercial mining will be completely banned. The following year, in 1965, gravel mining was completely banned throughout the entire Tama River, and the history of gravel mining came to an end.
References cited. “Inagi City History Volume 2”
“Folklore of Inagi City (4)” “Inagi Things and Life 3”
Gravel winnow and jolen used for gravel mining
A gravel mining hole in Daimaru (photographed by Hideo Hamada in 1964)
A machine ship for gravel mining (around the end of the Taisho era)
Deterioration of the riverbed due to over-digging (1988)
Gravel railway around Inagi in the early Showa period
