Remarks on the Bomarc

I was excited to see the build article on the Bomarc missile by Jim James in the May/ June 2023 issue. I have a long standing interest in this missile, along with the SAGE radar/computer system that controlled it for air defense.

Jim gave a lot of helpful information in his article, but there is one major set of errors he introduced: He gives a set of two different size fan blades to add to the center body and the two ramjets.

While the fan blade art provided was very nice and may be useful elsewhere, neither the Bomarc rocket boosters nor ramjets had fans. In the Bomarc A series, the center body housed a liquid fuel rocket (hydrazine and nitric acid) to boost the missile to ramjet ignition speeds of around Mach 3. The later B model replaced the liquid fuel rocket with a Thiokol solid rocket booster in the center body. Neither rocket system had any internal fan structures.

Likewise, the two sustainer Marquardt RJ43 ramjets do not have any fans in the intake or exhaust. The inlet spike and shape of the internal area ramp design of a ramjet engine compress the air without fans.

Again, overall this was a very helpful article in tips for updating this 1950s vintage kit recently re-released by Atlantis Models. – Tom Dougherty Ayer, Ma.

Ed.: Thanks or writing, Tom. I forwarded your email to Jim and here’s what he said:

“Glad that you found the article useful and appreciate your comment about ramjets and main engine. To be honest, I was more interested in filling the gaping holes in the engines than striving for accuracy. My unfamiliarity with the actual workings of the Bomarc led me to the simplified solution of the fan inserts.”

Hey, we’ve all been there before when we find out that bit of info after the model was finished. - A.S.