1943 Rochester, New York.
High fences, guarded entrances.
An unmarked industrial building where the neighbors had no idea what was being made inside.
Eastman Kodak, a company known for cameras and film, had been pulled into a different war entirely.
On the assembly line, workers handled something that looked harmless, familiar, almost comforting.
White leather, red stitching, perfectly round, a baseball.
Except it wasn’t a baseball.
It was a hand grenade designed to explode the instant it touched anything.
No delay, no warning, no chance to throw it back.
American military planners believe they had found a solution to one of infantry combat’s most dangerous problems.
Traditional grenades relied on time delay fuses.
Pull the pin, throw, wait several seconds.
In theory, that delay protected the thrower.
In reality, it gave experienced enemies an opportunity.
German veterans, particularly those hardened on the Eastern front, had learned to react quickly.
Some accounts describe grenades being grabbed and thrown back before detonation.
Others describe soldiers timing the fuse almost instinctively.
The weapon meant to clear a position could return seconds later to kill the man who threw it.
The answer seemed obvious.
Remove the delay, make the grenade explode on impact.
But that idea had defeated engineers for decades.
A device sensitive enough to detonate on contact was also sensitive enough to explode when dropped, bumped, or mishandled.
Every army understood the trade-off.
Most accepted the risk of delay because it was predictable.
The OSS chose a different path.
The concept is often linked to Colonel Carl Eiffeler commanding OSS Detachment 101.
He noticed something nearly universal among American soldiers of that era.
They all knew how to throw a baseball.
Not just adequately, but instinctively.
The motion was learned in childhood.
No training required.
Eiffel asked a simple question.
What if the grenade matched the thrower instead of forcing the thrower to adapt to the grenade? The OSS research branch embraced the idea immediately.
Stanley Levelvel, head of OSS research and development, specialized in unconventional weapons, exploding coal, concealed devices, tools designed to create surprise rather than brute force.
A baseball grenade fit perfectly into that mindset.
The requirements were strict.
The grenade had to feel like a baseball.
It had to detonate on impact with any surface.
It had to remain inert during carrying and throwing, and it had to be simple enough for any soldier to use without instruction.
Eastman Kodak received the contract.
The company had precision manufacturing experience and facilities that could be converted quietly.
The weapon was designated T13.
The fuse was designated T5.
Almost immediately, engineers ran into reality.
A regulation baseball weighed just over 5 o.
That weight left little room for explosives, a fuse mechanism, and a steel casing.
The final product more than doubled the intended weight.
It still looked like a baseball, but it no longer behaved like one.
The explosive charge was powerful, far stronger than the TNT used in standard grenades.
The casing was thin, designed to fragment evenly.
On paper, the results were impressive.
Fragment density exceeded existing grenades.
Range improved.
Accuracy improved.
The heart of the design was the impact fuse.
The thrower gripped a weighted butterfly cap with two fingers, mimicking a baseball grip.
When thrown, the cap separated and trailed a nylon cord.
When the cord reached full extension, it pulled a secondary pin.
The grenade was now live.
Any impact would trigger detonation.
It was clever.
It was elegant, and it left no room for error.
Testing began at Aberdine Proving Ground.
Early results seemed promising, but problems emerged quickly.
Some grenades detonated when dropped from heights far below specification.
Others reacted unpredictably during handling.
The most dangerous flaw was the throwing motion itself.
If the thrower’s grip slipped or if the butterfly cap jerked prematurely, the arming sequence could complete while the grenade was still in the hand.
The natural follow-through of a throw could bring the armed grenade back into contact with the thrower’s body.
On November 3rd, 1944, a civilian tester threw one straight up to observe Fuse behavior.
It armed on the way up.
It came down on his head.
He was killed instantly.
The incident was documented.
Testing continued.
By mid 1944, hesitation was no longer acceptable.
Casualties were climbing.
Major operations were underway.
Commanders believed any potential advantage was worth the risk.
Engineers made small adjustments to reduce sensitivity, but there was no breakthrough.
On June the 2nd, 1944, just 4 days before the Normandy landings, the Army approved largecale production.
Manufacturing accelerated.
Training protocols tightened.
Accidents were treated as acceptable losses.
Thousands of grenades now existed, moving forward on momentum rather than confidence.
In February 1945, roughly 10,000 were shipped to Europe for field trials.
This was where the weapon would prove itself or fail completely.
It failed.
Nearly 10% did not detonate at all.
Cold weather stiffened internal components.
Mud, snow, and water absorbed impact energy.
Some grenades landed and simply sat there.
Worse were the premature detonations.
Some armed too early during the throw.
Others detonated unpredictably.
Two American soldiers were killed.
Dozens more were wounded.
The weapon now had the worst possible combination.
It was unreliable against the enemy and dangerous to the user.
On March 22nd, 1945, General Joseph Stillwell ordered all testing stopped immediately.
Production was suspended days later.
With the war nearing its end, orders followed to destroy existing stock.
No confirmed enemy casualties were ever documented.
The grenade harmed its creators instead.
British forces had chosen delay and discipline.
German forces used leverage and distance.
Both accepted predictable risk.
The American solution was the most ambitious and the most dangerous.
Modern impact grenades exist today using sensors and electronics unavailable in the 1940s.
The idea itself was sound.
The technology was not ready.
Most TN13 grenades were destroyed exactly as ordered.
A few survive behind museum glass.
They remain evidence of how urgency can outrun engineering and how even brilliant ideas can become liabilities when reality refuses to cooperate.
The baseball grenade was meant to turn instinct into advantage.
Instead, it turned familiarity into danger.
Sometimes the most dangerous weapons are not the ones aimed at the enemy, but the ones trusted too early by the people holding
