|
|tracklength = |gauge = 〔Majewski 2000, p. 134.〕 |el = |speed = |hielevation = |lowelevation= |height = |notrack = 1 |grade = (1.326%)〔Drinker 1893, p. 1072.〕 |}} The Brookville Tunnel (also Brooksville Tunnel) was a historic railroad tunnel engineered by Claudius Crozet during the construction of the Blue Ridge Railroad in the 1850s. The tunnel was part of a series of four tunnels used to cross the Blue Ridge Mountains of Virginia for the Virginia Central Railroad of the United States. The Brookville Tunnel was the second tunnel used to cross the mountains from the east (the easternmost being the Greenwood Tunnel), and was located approximately west of the village of Greenwood, Virginia. During its construction, numerous cave-ins and landslides occurred because of the fragile and weak rock the tunnel passed through, and at one point, an outbreak of cholera forced work to stop. By October 1856 the tunnel was completed at a cost of $114,600, having been lined with a thick elliptical brick arch to hold back the earth. The Brookville Tunnel was used by the Virginia Central Railroad, and after 1868, the line's successor, the Chesapeake and Ohio Railroad. After the reorganization of the line in 1878 as the Chesapeake and Ohio Railway, the tunnel continued to be used until it was demolished and replaced by a cut during the construction of Interstate 64 in the 1960s and 1970s, at which point it was one of only two of Crozet's original four tunnels still in use. ==History== On March 5, 1849, the Virginia General Assembly passed an act to incorporate the Blue Ridge Railroad. This railroad was to construct a rail line over the Blue Ridge Mountains for the Louisa railroad (renamed as the Virginia Central Railroad in February 1850) from a point near Blair Park at the eastern base of the mountains to Waynesboro in the Shenandoah Valley via Rockfish Gap.〔Virginia General Assembly 1849, p. 30–31.〕 Claudius Crozet was appointed as chief engineer of the Blue Ridge Railroad and developed a plan to cross the mountains using a series of four tunnels.〔''History of the Chesapeake and Ohio Railway''.〕 The first tunnel from the east was the Greenwood Tunnel, built through a difficult and insecure ridge near Greenwood.〔Historic American Engineering Record, p. 4.〕 Brookville tunnel was located west of the Greenwood Tunnel,〔Google Maps – Distance Between Greenwood and former Brookville Tunnel〕 also built through a small offshoot spur of the Blue Ridge Mountains.〔Drinker 1893, pp. 886–888.〕 Construction on the Brookville Tunnel, or the "middle"〔Virginia Central Railroad Company 1853, ''1853 Report'', p. 25.〕 or "second tunnel"〔Crozet 1853, p. 282.〕 as it was then called, was begun sometime between 1849 and 1851.〔〔 The earth encountered at Brookville was of a much weaker quality than at the Greenwood Tunnel, rendering the digging of the tunnel both an extremely dangerous and difficult task. Although the eastern section of the ridge was composed of firm and sturdy rock,〔 the majority of the tunnel passed through a mixture of frail slate that was formed at a steep angle, soapstone, and clay.〔〔Couper 1936, p. 147.〕 When exposed to air, this mixture would often disintegrate causing large amounts of earth to fall into the tunnel bore.〔〔Logan 1998, p. 8.〕 On two occasions during the tunnel's construction, though great care was taken to provide temporary support, major cave-ins occurred forming craters on top of the ridge, as much as above the tunnel.〔〔Crozet 1857, p. 406.〕 Another slide occurred on the outside of the western portal that blocked the entrance to the tunnel and prevented workers from repairing the damage from the two internal cave-ins.〔Crozet 1857, pp. 406–407.〕 Rocks often fell down upon the timbers under which the men worked, creating sounds described as "resembling that of distant thunder".〔Couper 1936, p. 148.〕 The weakness of the earth, especially in the western sections, necessitated the implementation of a strong arch throughout approximately of the tunnel and a durable brick lining.〔Drinker 1893, pp. 887, 1072.〕 Crozet described the nature of the work on the tunnel in an 1854 letter: The Brooksville Tunnel is the most difficult work of the kind, I have seen any record of: at the Western entrance, the pressure of the big slides actually causes the bottom to surge up, as is sometime the case in coal mines; in view of the sliding tendency and immense pressure of this ground, it will be advisable to enter on that side with an invested arch to prevent a collapse...This work is vastly more difficult than the Greenwood Tunnel was, though it was not, by any means, an easy safe job.〔Crozet 1854, September 1.〕 By this time, the tunnel had come to be known as the "Brooksville Tunnel," after a small stagecoach stop and inn nearby where Crozet's headquarters was located;〔〔Couper 1936, p. 161.〕 in later years, the "s" was dropped and the tunnel was simply referred to as the "Brookville Tunnel."〔〔〔Logan 1998, p. 13.〕 In late summer of 1854, an epidemic of cholera broke out among the Irish workers at the tunnel. In a letter to the Virginia Board of Public Works, Crozet states that the epidemic began at the eastern end of the tunnel where around 25 of the total 150 workers perished from the disease. The disease then spread to the western end where another eight workers died before work ceased. During this outbreak, little work could be done on the tunnel, adding yet another delay to the difficult work the Brookville Tunnel posed.〔 While work on the tunnels continued, the Virginia Central Railroad, eager to connect its eastern division to the line under construction in the Shenandoah Valley, developed plans to use temporary tracks to bypass the incomplete Blue Ridge Railroad.〔Virginia Central Railroad Company 1853, ''1853 Report'', pp. 12, 20–22.〕〔Dixon 2008, pp. 6–7.〕 As was done over Rockfish Gap to the west, a temporary track approximately long was proposed by the Virginia Central Railroad's Chief Engineer, Charles Ellet, Jr., and constructed around the Brookville Tunnel as the digging continued.〔Dixon 2008, p. 7.〕 Due to the many setbacks and difficulties encountered, the tunnel was not completed until October 1856, just two months prior to the hole-through of the Blue Ridge Tunnel at the top of Rockfish Gap.〔Crozet 1857, p. 407.〕〔Sweet 1998, p. 20.〕 Remarkably, with the exception of the cholera outbreak, no one was injured during the dangerous work completing the Brookville tunnel.〔Couper 1936, p. 157.〕 The Virginia Central soon after began routing trains through the Brookville tunnel, avoiding the short temporary track.〔Couper 1936, p. 158.〕 During the American Civil War (1861–1865), a large crack was found within the tunnel's arch, being in some locations as much as wide. Upon examination of the earth above the tunnel, it was found that a section of the earth had slipped, and was resting on the tunnel walls. With the tunnel in danger of collapsing, a plan to address the tunnel's structural issues was developed that put in place a second arch below the original.〔 The new arch was started above the rails〔Virginia Central Railroad Company 1864, ''1864 Report'', p. 30.〕 and rose to a peak just above what was necessary to clear a brakeman riding atop a railroad car (at that time, ),〔Drinker 1893, p. 887.〕 around below the original arch.〔 Because of the ongoing war and the lack of funds and resources, the new arching could only be completed in segments.〔 It was deemed necessary to re-arch a total of of the tunnel, and as of 1864, had been completed at a cost of $23,390.73 (Confederate dollars).〔 After the war, the tunnel continued to be used by the Virginia Central Railroad, and after 1868, the Chesapeake and Ohio Railroad.〔Chesapeake & Ohio Railroad Company 1869, ''1868 Report'', p. 14.〕 The Chesapeake and Ohio Railroad was reorganized as the Chesapeake and Ohio Railway in 1878,〔 and continued to route trains through the tunnel up until the tunnel's demolition with the construction of Interstate 64 in the 1960s and 1970s.〔Logan 1998, p. 12.〕〔 At the time of the tunnel's demolition, it was one of only two of Crozet's original four tunnels of the Blue Ridge Railroad still in operation (the other, which as of 2013 is still in use, was the Little Rock Tunnel).〔〔Dixon 2008, p. 10.〕〔Google Maps – Aerial View of Little Rock Tunnel〕 Today, Interstate 64 passes over the cut that replaced the Brookville Tunnel.〔Dixon 2008, p. 8.〕〔〔Google Maps – Aerial View of Former Brookville Tunnel〕 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「Brookville Tunnel」の詳細全文を読む スポンサード リンク
|