I've just published version 2.3 of Motorcade 63:
https://www.marktyler.org/mc63.htmlThere are no major changes this time, just small improvements in various areas. However, I have included a second animation at the bottom of the above web page which explores the ideas that were first established by the HSCA acoustics scientists regarding the position of a microphone in Dealey Plaza (it was originally suspected as being on the bike ridden by HB McLain). Over the last 20 years or so these ideas have been refined by others such as Don Thomas, and recently explored by Josiah Thompson in his recent book "Last Second In Dallas". Acoustic science is a somewhat dry and esoteric topic, so I thought it would be useful to have an animated version of this scenario so all researchers can see in real time what the practical implications are regarding the motorcade vehicles and timing issues.
In the main animation I have placed McLain in the positions established by the Hughes film (circa Z150), the Dorman film (circa Z410), and also the DCA film when McLain was on Main Street just before entering Dealey Plaza (and briefly by the Paschall film a few seconds later). However, in the HSCA scenario I have McLain's bike travelling around Dealey Plaza to be consistent with the acoustics analysis, and also consistent with the photographic record. Several important issues regarding continuity arose during this work:
- I had to assume that the bike we see in the Hughes film at Z150, and the Dorman film at Z410, was officer JW Courson (nothing else seems to fit the evidence). In doing this both McLain and Courson moved forward by some 100-200 feet from the positions established by other earlier photographs in the motorcade such as this Dillard photo which shows McLain (bike id 352) near the camera cars:
- This position was maintained just before McLain entered Dealey Plaza as proven by the DCA film:
- At the end of the Hughes film segment where the Presidential limo had just turned onto Elm Street, we see Houston Street without any bike visible:
- This was about 3.2 seconds before the Zapruder film restarted at Z133. Using the shot timings from the dictabelt where the Z313 shot was fired from the grassy knoll, I have put McLain in the position to record the first gunshot at Z175 which is 2.3 seconds after Z133, or 5.5 seconds after the Hughes film frame above was recorded. The animation assumes that McLain was just to the right of this film frame and sped up as he travelled the 200 feet in those 5.5 seconds (which is an average speed of 36.4 ft/sec or 24.8 MPH). The animation also includes acceleration and deceleration near the street corners which pushes up the peak speed of McLain's bike to about 30 MPH.
- I'm not aware of any contradictions between this animated scenario and the known photos and films taken during the time period studied, but if anyone thinks there is a contradiction please let me know.
Although this new animated HSCA scenario is theoretically possible, with nothing in the photographic record to contradict it, the speed of McLain's bike is completely preposterous due to the rapid acceleration along Houston Street (why would he be motivated to do such a thing?). By contrast, the main animation has the bike moving around Dealey Plaza at its usual speed of 5-10 MPH and in close proximity to the camera cars, which is consistent with the earlier stages of the motorcade (and also in formation with Marrion Baker to McLain's right, with Courson in formation with Clyde Haygood further back).
As always, I'm happy to receive constructive feedback from others so I can improve the work and fix errors or omissions. I'm especially interested in hearing from people who still believe the HSCA acoustics work is correct, but think that my animation positions for McLain are wrong (or if the microphone was on a different vehicle).
For a historic view of these issues, here are web links to very thorough articles written by Don Thomas and Dale Myers from 2008-2010:
https://www.maryferrell.org/pages/Essay_-_The_Bike_With_the_Mike.htmlhttps://jfkfiles.blogspot.com/2010/11/jfk-assassination-acoustics-and.html
