Who Built These Mysterious Concrete Arrows? | HowStuffWorks

这款混凝土箭头仍然是美国早期跨大陆航空标签系统的最后痕迹之一，仍然存在于加利福尼亚州核桃溪以外的沙漠中。Wikimedia Commons（CC BY-SA 3.0)

Dotted across the American landscape in rugged, isolated places where tumbleweeds roll, snakes skitter and coyotes howl in the night, huge, mysterious concrete arrows lie like forgotten monuments against a pallet of sagebrush and sand, or on high hills against a backdrop of snow-capped mountains. Are they outcroppings of an ancient underground geometric civilization? Signposts created by aliens to invade Earth? Remnants of the Pony Express – a lost episode that never aired on the History Channel?

不，以上都不是。但是，这些巨大的破裂和边缘磨损的箭确实指向历史：它们是美国早期跨大陆航空信标系统的最后遗迹 - 从字面上看highway of light– that guided early 1920s airmail pilots, in the days before radar and ground-to-air radio, safely to their destinations as they made night flights from coast to coast.

Nearly a century before satellites,Siri和全球定位系统made ace navigators out of even the most directionally challenged among us, pilots back in the day had to rely on their compass and terrestrial landmarks like mountains, lakes, rivers and railroad tracks to guide the way. Because their open cockpitbiplaneshad no lights and landing fields weren't illuminated, they could only fly by day, or risk almost certain death.

因此，早期的跨大陆航空邮件交付是一种混合情况，涉及白天通过空中飞跃到全国各地的邮件，并将其运送到夜间隆隆声的火车上。使用该系统，在1922年尽可能快地进行一封信，可能需要长达83个小时才能从纽约到旧金山。然而，到1926年，由于信标系统的出现，到了33小时的出现时，当点燃的气道到位时，可以在短短33小时内从纽约送到旧金山。然而，成为天空的邮递员仍然是危险的和潜在的致命工作：在1918年至1927年之间，有230名飞往邮局（美国邮政局的前身）的男子中，有32人在撞车事故中死亡，仅在运营的第一周就丧生。

Ground-based Visual Navigation

1924年，国会批准了美国邮政服务的资金，以建立一个基于地面的视觉导航系统。在邮政服务的指导下，灯塔局的航空公司部门创建了带有混凝土箭头的信标站。1926年，监督传给了新的AeronauticsBranch. Here's how itworked: A series of horizontal 50 to 70-foot (15 to 21-meters) long concrete arrows painted bright chrome yellow were spaced approximately 10 miles (17 kilometers) apart.

At the center of each giant arrow stood a 51-foot (16-meter) steel beacon tower topped with two rotating lights estimated at between 1.25 and 5 million candlepower which, in clear weather, could be seen by pilots for 10 to 40 miles (17 to 64 kilometers). Beneath the rotating lights, two course lights pointed forward and backward along the arrow – flashing a code which identified the beacon's number. Where no electricity was available, a generator shed, located at the tail end of the arrow, fueled the acetylene gas-powered lights. The site number was painted on one side of the shed's roof and the airway on the other side. Each giant yellow arrow pointed to the next giant arrow in a system of sequentially numbered beacon stations that guided pilots safely along their routes.

By 1933, some 1,500 towers and信标全国大约有18,000英里（29,000公里）的不同路线。在整个1930年代，高级导航和无线电技术取代了视觉陆基系统，大萧条期间运行箭头和信标系统的高昂成本终于使其过时和过时了 - 尽管少数信标继续以最小的容量运行1940年代。一旦该计划获得资金，商务部就退役并解构了大多数塔楼的塔楼，这是第二次世界大战期间短暂供不应求的急需的钢铁，留下了一条越野大型，寂寞的，鲜艳的黄色混凝土箭头，以至于天气和天气和天气和从上下文中消失了将近一个世纪。

输入箭头猎人

向前闪到2018整个美国的箭头。Some retired couples buy metal detectors and head for the beach. This intrepid couple grabs their cameras, puts on their hiking boots, buys a Jeep and a drone and hits the highways and byways of America in search of arrows.

在为信标系统创建的大约2,000箭中，据估计约有200个remain。史密斯（Smith's）的发现并记录了一个相当大的数字，考虑到他们仅在2013年开始任务，并在布莱恩（Brian）徒步旅行到内华达州沃沃（Washoe Co.）的第一个发现之后被迷住了。他从现场发送了夏洛特的照片，因为膝盖的关节炎使她很难爬。

尽管如此，她坚持不懈。

"We have 126 concrete arrow photos on our homepage, two destroyed sites, six metal arrow sites and five other type arrow sites," says Charlotte in an email. "We're finding new sites all the time. When we first started looking, Google maps didn't have clear images for all locations but as they redo areas sometimes an arrow is located. If the site has winter satellite photos it is easier to find the arrow under the trees than in a summer photo. In the East, there is a lot of foliage hiding the arrows and many sites don't have clear ground photos yet. So as better satellite photos are taken we expect to find more arrows. Also, as more people hear about them, they're out looking for them and send us the location when they find one."

史密斯夫妇认为他们的箭头任务是他们俩都喜欢的爱好 - 一种爱好，使他们能够旅行美国在亚利桑那州温斯洛的Harley-Davidson Room等凉爽的地方，在新墨西哥州罗斯威尔停下来学习外星人，拍照在有趣，偏远的位置和驾驶无人机的箭头。

夏洛特说：“我们一直在电视上，在报纸和杂志上 - 对于'退休的老人'，这并没有比这更好的。”“新闻报道称呼我们年龄的人，但我们肯定不会感到年纪大！我们首先开始。我们不知道有多多，因为我们是多少。我们想认为我们散发出了激励改进的光线，但没有人告诉我们我们是他们的灵感。”

在过去的12个月中，他们的命中率超过1600万website– 12 million of those in the last nine months alone. That's a lot of curiosity.

夏洛特说：“我认为人们最感兴趣的是让我们感兴趣的事情。”“我们从未听说过箭头，我们不知道这些东西存在，仍然可以找到。我们想看到一个，然后是另一个，直到我们亲自访问并在19个州拍摄了94箭。”

Speaking of curiosity, Charlotte wonders if anybody reading this might have any old pictures or documents concerning historic airmail sites, and she believes it's possible some folks do (if so, please visit the Smith'swebsitefor contact info – they'd love to hear from you).

“许多中级着陆场都有看护人，家庭住在田野里。我们知道pictures在某个地方。查看您的旧家庭相册。也许您是一个帮助飞机飞行并不知道的人的后代！”

另外，夏洛特和布莱恩从未去过双翼飞机，都希望有一天能飞过一只箭。