posted 04-27-2010 01:23 PM               

I understand that Apollo 4 launched before NASA had developed any type of noise suppression or water suppression system on Pads 39A and 39B. There's eyewitness accounts stating that windows were shattered six miles from the launch pad.

Also, many of us remember Walter Cronkite's emphatic words as the CBS trailer window and ceiling started caving in on top of him.

posted 04-28-2010 10:17 AM               

quote:

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Originally posted by Go4Launch:
As far as windows broken six miles away, that seems unlikely; I'd like to see the source. Cronkite's window, 3.4 miles away, survived.

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I still think it's plausible. Some glass is thinner and more brittle than other glass...and some glass is more susceptible to certain frequencies. Also, Cronkite was holding the glass to keep it from flexing any further, which likely helped it survive.

posted 04-28-2010 08:45 PM               

There is also another building, about a mile north of the KSC Industrial Area, that is within the 6-mile radius when AS-501 was launched in Nov. 1967.

posted 04-28-2010 10:48 PM               

There are glass structures right at the pad, and they are unaffected. Sound may vibrate and rattle and shake things pretty well, but it's not the loudness that would shatter glass, it's the pitch, and you need a high pitch to do that.

Cameras, for example, survive and fire normally right at the pad. Nothing six miles away is affected.

posted 04-28-2010 11:23 PM               

quote:

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Originally posted by Go4Launch:
Cronkite's window, 3.4 miles away, survived.

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Only then did the shockwave reach the press site 16,000 feet away, traveling through the ground and the air. Staccato bursts, rapid and thunderous, shook the small wooden grandstand, rattled its corrugated iron roof and pushed in the plate glass window on the Columbia Broadcasting System's new mobile studio.

Walter Cronkite, the C.B.S. commentator, and his crew caught the window and held it in place as they continued describing the launching.

Reporters in the open could feel the pressure of the shockwave beating their faces and chests.

Engineers estimated the noise reached about 120 decibels at the press site, the equivalent of a piston-engine airplane warming up only a few feet away. The "threshold of pain" for loud noises, they said, was 135 to 140 decibels.

posted 04-29-2010 05:27 AM               

quote:

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Originally posted by Ben:
There is no way any windows were broken six miles away.

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I do recall on many occasions though, while living in a home on central Merritt Island during the Apollo era, quite often would my windows vibrate, rattle, and shake within minutes of a rocket liftoff.

posted 04-29-2010 06:33 AM               

Walter Cronkite, the C.B.S. commentator, and his crew caught the window and held it in place as they continued describing the launching.

posted 04-29-2010 11:29 AM               

As for being three miles away from the pad, are we sure the CBS trailer was that close? Reason I ask is if I recall correctly, the press site of today sits more like four miles away and it sits at about the same distance away as the launch control center from pads 39A and B (B is a little closer then A). The Center was placed where it was as engineering estimates figured it was just outside of range of the biggest piece of a Saturn 5 or the pad structure being hurled that far in case a rocket exploded on the pad (lighter stuff could fly further, but the LCC had blast shutters to shield it in case that happened). As such, if the press site is a bit closer, I find it as something of a twisted joke that the press would be in more danger then the controllers in their hardened bunker a couple blocks away. It seems even crazier if the news crews were allowed to witness Apollo 4's launch from an even closer range then that.

As for windows breaking at 6 miles, if it did happen, then it more then likely would have been due to the structure surrounding the window allowing it to pop out and shatter as opposed to a pressure wave directly causing the pane to shatter. Sound can be a tricky thing though as atmospheric conditions such as air density and relative humidity (and wind direction) can cause the sound to behave a little different at each rocket launch. Terrain features can also amplify or deaden sound a little as well.

posted 04-29-2010 03:50 PM               

And pad A is closer (3.05 miles from the center of the MLP to the clock, 3.18 to the network buildings) than pad B (3.41 and 3.50).

posted 04-30-2010 09:51 AM               

The original design of the TSMs, as used on AS-500F, Apollo 4, and (apparently) Apollo 6 during its roll out used a "clam shell" design:

However, prior to the Apollo 6 launch the TSMs were redesigned to the more familiar "hooded" design:

All of the TSM documentation I've found dates from before Apollo 4's launch and shows only the clam shell design. I've never read anything about the actual redesign; the only thing I've ever found related to the matter was a single sentence in the AS-501 Flight Evaluation Report

All tail service mast hoods were carried away by exhaust blast allowing the aft umbilical carriers and service lines to be damaged by engine blast and fire.

posted 04-30-2010 03:41 PM               

In preparation for the next Saturn V launch (AS-502), some major changes were made. In fact, the hoods together with all of their closing mechanism and hydraulics were abolished; in their place went the simplest imaginable protection.

A lattice tower was erected on top of each TSM at the top of which was mounted a hood with a visor -- very much like a knight's armored helmet. Once the visors are raised and latched in position, while operating both TSMs, the masts swing upwards and when they have entered their respective hoods, the latches are tripped and the visors slide down over their fronts so that all is covered.