API 6A GATE VALVES

Craters of the Moon Thermal Area (or Karapiti in M
ori language) is a region with geothermal activity north of Taupo, New Zealand. It is a part of Wairakei, the largest geothermal field in New Zealand, with a surface area of about 25 km2, which lies in the Taupo Volcanic Zone.

The name springs from the many hydrothermal eruption craters, which are in part barren and which have bright colours. Combined with the numerous steam vents, constantly shifting, collapsing and reforming giving the whole area desolate appearance, and the sulphur smell, the whole area has an “unearthly” atmosphere. The craters are a relatively recent feature of the area and appeared as a result of human activity in the region.

In 1859 Ferdinand von Hochstetter, an Austrian geologist who traveled through the area, reported a colossal column of steam from the Karapiti Blowhole (fumarole), observable from about 20 km away. It was difficult to approach because steam vents and springs covered the valley floor and the ground was warm, soft, iron-stained clay for great distances around.

By the beginning of the 20th century the Blowhole was a tourist attraction, albeit not of the level of the nearby Wairakei Geyser Valley. It's worthwhile reading the “Impression of a Trip” in 1927, in which the Karapiti Blowhole is named “the safety valve of the North Island”:

”After dinner (which was served at 6 p.m.) we took our seats in the car which went to Karapeeti (the safety valve of the North Island) and the “Huka” falls, a little higher up the Waikato.

Karapeeti blow hole is an escaping volume of superheated steam with a pressure of 180 lbs. to the square inch coming through an aperture two feet by one foot. The guide lit a sack sprinkled with kerosene so that the visitors could see the escaping steam in the darkness and after the sack had partly burnt away he picked it up on a stick and shook the burning pieces down into the blow hole. These were immediately carried up in the jet of steam and presented a very weird fireworks effect, the sparks remaining alight, proving that it was super-heated or dry steam. This blow hole, according to Maori tradition, has been constant for the last 200 years and the Maoris of the early days of New Zealand used this column of steam as a beacon to guide them with their canoes across Lake Taupo which is six miles distant.”

Fowler 3F 0-6-0T 47383 lifts its safety valve as it waits for the off on a train to Kidderminster.

Built by the Vulcan Foundry in 1926 for the LMS 47383 ran in British Railways service until 1967 when it was withdrawn from Newton Heath shed in Manchester. It is currently a static exhibit in the Engine House at Highley.