This is great news!
What alloy are people using? 300 series stainless steel?
Regards,
William Schmiedlin
On Wed, Mar 27, 2019, 10:45 AM Rick Maschek <dmarc-noreply@xxxxxxxxxxxxx>
wrote:
Somehow I thought this had been announced here. Some of you may already be
aware.
This is a post by Steve Shannon, TRA President on the TRA forum from last
month:
*"At LDRS 36 in 2017, Rick Maschek requested the Board to consider
amending the Tripoli Research Safety Code to allow steel nozzles for use
with sugar motors used at Tripoli Research Launches. At the time we
requested that he provide data to our Tripoli Research Committee Chair, Dr.
Terry McCreary, to demonstrate that the use of sugar motors would not
increase risk. The concern as I understand it is that the additional
density of steel would lead to increased momentum and thus greater range in
the event of a nozzle being spit. The counter to that is that nozzles in
properly flying rockets are spit downward rather than horizontally. For
static tests it's possible to require that they be held vertically so the
direction of a spit nozzle would be vertical and thus have limited
horizontal range. NFPA does not prohibit steel nozzles. Since that time
Rick and Terry and I have discussed this electronically several times, but
we never did really receive data. Honestly, most of us don't feel that
steel nozzles necessarily increase risk when used for sugar motors as long
as all other rules are followed. So, rather than leaving this unresolved,
Terry proposed that we provisionally allow the use of steel nozzles with
sugar motors for both static burns and flights as long as the static burns
are vertical. The board voted on his proposal last week and it passed
easily. The motion was for steel nozzle usage to be allowed for this
calendar year (2019). During that time we want Prefects and users to come
to this thread and relate any first hand accounts about their use of steel
nozzles, both good and bad, and especially observations about spit nozzles.
Of course for flights, an angled blast deflector could redirect a spit
nozzle, so observations about that should also be made. At the end of 2019
Terry and the board will review the data and make a determination whether
to incorporate that change permanently in the Tripoli Research Safety Code.
If we do nothing, this provisional permission to use steel nozzles will
expire at the end of 2019. I should also point out that this is not
mandatory. Local Prefects have the latitude to ban the use of steel nozzles
at their home fields. Local Prefects always have the authority to adopt
policies that exceed NFPA and the Tripoli Safety Codes."*
Rick
