Since it's New Year's Eve, Here's Another


#1

I got this from an antique shop. I was told that this bomblet was bought from Kauffman’s on 42nd street in NYC about 45 years ago. The guy told me that WWI pilots dropped handfuls of these from high above the trenches and they acted as bullets powered by gravity. Any truth to this story? This thingy is about 1.5 inches tall with no markings at all.


#2

yellow dog,lazy dog looks like a vietnam era one to me.

It NOT a WW I version for sure.

They sell for .99 cents around here.


#3

Thank you, Cobb,
According to internet sources, regardless of how they were released into the air, each “Lazy Dog” projectile would develop an incredible amount of kinetic energy as it fell, penetrating nearly any material upon hitting the ground. Some reports say that their speeds often exceeded 500 mph before impact. If true, it would mean that each individual impact had more energy than a .50 caliber bullet. They were developed at the end of WWII.


#4

Vlad

None of my business, but can a falling object reach a speed of 500 mph? I thought that terminal velocity was more like 200 MPH.

That’s still pretty fast if it hits you in the head. :) :)

Ray


#5

Ray, the British ‘earthquake’ bombs of WW2 (Tallboy and Grand Slam)reportedly went supersonic before impact. It’s all a question of the ballistic coefficient…


#6

To my knowledge it was adopted in 1954 with the MK44 500lbs cluster bomb which contained about 17,500 of these. Used in Korea and some even in Vietnam.


#7

Lots of factors involved with a object reaching terminal velocity in Earth’s atmosphere. A couple of examples:
a round ball weighing 10 lbs with .5 square foot cross sectional area and a drag coefficient 0f .5 dropped from 10,000 feet would reach a teminal velocity of 213.52 feet per second or roughly 145 miles per hour. Change the cross section area to .25 and you get 301.963 fps or 205.88 mph.

factors in NASA’s calculator are:

  1. Weight
  2. cross section area
  3. drag coefficient
  4. altitude

for more see: grc.nasa.gov/WWW/K-12/airplane/termv.html

Another factor to be considered would be be the speed the delivery vehicle was traveling but this is all beyond me!!


#8

Maybe I’m doing something wrong but with a weight of 1000 grains, cross section of .1 feet, a BC of 1.0, dropped from 10,000 feet = terminal v of only 50 mph.

And those are generous input numbers.

???

Ray


#9

Ray–That sound about right to me. A short time ago the program “Mythbusters” did an examination of the lethality of bullets fired straight up and then falling back to earth, like you see all the time in celebration. They found, using a M1 Grand .30-06 with 180 gr. bullets that, due to wind, the bullets generally fell within 30 feet of the firing point and buried, at most, about 2 inches in semi-soft ground. Many of the bullets were even found just laying on the surface. So, the impact could not have been very fast. They concluded that you would most likely receive a nasty bump on the head, but they would not be lethal.


#10

A quote from “Bombs Gone” by MacBean and Hogben (the standard reference on British aerial bombs) concerning the 4,000 lb Tallboy S bomb (a highly-streamlined medium-case bomb, the little brother of the 12,000 lb Tallboy and 22,000 lb Grand Slam):

“Released from the optimum height of 18,000 feet at an air speed of 169 mph, the bomb took 37 seconds to reach the ground, impacting at just over 1,100 ft per sec (750 mph)”.

Obviously, the ballistic coefficient of a 4,000 lb bomb is going to be many times that of a small object.


#11

Tony
I don’t know the cross section area and drag coefficient of the bomb you mentioned (or any bomb for that matter), but by using that of a sphere with a 10 square foot cross section area (just a guess) NASA’s calculator comes up with speed very close (1087 fps) to the one you quoted.
Phil


#12

The amusing thing about all this is the implications for Galileo’s famous experiment of dropping two different weight balls from the Tower of Pisa, to show that Aristotle was wrong about the speed of falling bodies being related to their weight. In fact, of course, Aristotle was right (although probably for the wrong reason) in that, other things being equal, bigger objects have higher ballistic coefficients, so they are less affected by atmospheric drag. However, the Tower of Pisa is not high enough to reveal this effect.


#13

[quote=“cobb”]
They sell for .99 cents around here.[/quote]
They are obviously common in the USA, unlike here. I saw one sell for


#14

BTT


#15

Haven’t I seen videos of lazy dogs being dropped from aircraft? Maybe they were something else but I recall that you could see the little buggers in flight. While 500 mph is not supersonic it is certainly not too much slower than a speeding bullet and you can’t see bullets in flight.

Just a Sunday morning observation and comment.

Ray


#16

Ray
If my math hasn’t failed me, 500mph is 733fps or fairly close to a 38 target load

60mph = 88fps, 500/60 = 8.33, 8.3*88 = 733fps


#17

World’s smallest projectile (bomb)? I got a story about it’s use from the guy I picked it up from. But, since it’s so unusual, I thought I would try to post some pictures and see if any one has ever seen one before. As usual, any input would add to my knowledge base about it. It’s 43mm tall. It’s to hard to explain so I will e-mail the pictures to Ray Merchant and see if he can post them. Happy New Year!


#18

Guessing a “lazy dog” type of gravity weapon?


#19

Here is AJ’s small bomb. And Tailgunner wins another Gold Star for ID without a clue. I’ll leave it up to someone else to post the story behind these little bomblets. When I was kid in the 1960’s every Army surplus store had a create full of these for a dime each. I hardly ever see them anymore.


#20

Here’s the plane used to drop those bomblets.

Sorry guys. My wife wants to stay up until midnight. That’s 3 hours to go and I’m getting giddy from lack of sleep.

ray