bennyfloydd
28th May 2011, 02:45
Hello folks,
This is my first post here and I hope I'm not being redundant. I did some hard Googling on this subject, and searched here as well.
Some of you may have stumbled across old aerial photographs of WWII and early post-war airfields that depict twin unbroken center lines running the length of the runway from threshold to threshold. Typically they run right through the touchdown markers, if any exist. The twin center lines seemed to disappear pretty soon after the beginning of the 1950's, in favor of a single broken center line marker.
I have tried hard to find details on the origin and purpose of these markings, but to date the only indirect explanation I have found relates to night or low visibility landings. The explanation states that the twin lines were set a fixed distance from each other, say fifty feet, which allowed crews to judge how high above the runway they were. It SOUNDS reasonable, since similar techniques were used by flying boats for water landings using wing mounted spot lights. However, finding any written historical record of them is proving elusive.
Does anyone have a 'line' on these markings?
For reference, I have added a link to the wonderful Hawaii Aviation archive. This link brings you to a series of photos of HNL taken during the very late 40's and early 50's, right at the time the twin center lines began to be replaced. In fact, a few pictures show some runways with single broken AND dual solid markings.
HNL Runways — Hawaii Aviation (http://hawaii.gov/hawaiiaviation/aviation-photos/1950-1959/honolulu-international-airport/hnl-runways)
Thanks in advance!
This is my first post here and I hope I'm not being redundant. I did some hard Googling on this subject, and searched here as well.
Some of you may have stumbled across old aerial photographs of WWII and early post-war airfields that depict twin unbroken center lines running the length of the runway from threshold to threshold. Typically they run right through the touchdown markers, if any exist. The twin center lines seemed to disappear pretty soon after the beginning of the 1950's, in favor of a single broken center line marker.
I have tried hard to find details on the origin and purpose of these markings, but to date the only indirect explanation I have found relates to night or low visibility landings. The explanation states that the twin lines were set a fixed distance from each other, say fifty feet, which allowed crews to judge how high above the runway they were. It SOUNDS reasonable, since similar techniques were used by flying boats for water landings using wing mounted spot lights. However, finding any written historical record of them is proving elusive.
Does anyone have a 'line' on these markings?
For reference, I have added a link to the wonderful Hawaii Aviation archive. This link brings you to a series of photos of HNL taken during the very late 40's and early 50's, right at the time the twin center lines began to be replaced. In fact, a few pictures show some runways with single broken AND dual solid markings.
HNL Runways — Hawaii Aviation (http://hawaii.gov/hawaiiaviation/aviation-photos/1950-1959/honolulu-international-airport/hnl-runways)
Thanks in advance!