Flashlight - once again

[trockey]

Hello,

I have been carefully reading information about the Dyatlov incident, and I have a few thoughts regarding the flashlights:

a)
When group left tent, they biggest problem, apart from the cold and fear, it was the darkness.
They were in complete darkness once their flashlights were exhausted.
So at begining, when flighlights was still operable, a person with the flashlight was extremely important for group close to the tent.

b)
The flashlight Dyatlov had used Zinc-Carbon batteries.
I remember these from the 1980s—they were very weak and unreliable.
In freezing temperatures, such flashlight could only shine for about 40 minutes  12 hours - so long??? (R20, D-type batteries)
And poor light ~15 lumens.
If Dyatlov left the flashlight on the tent, it means it had run out of power - then Diatlov left it (Really?)

c)
I don’t believe they used the flashlight as a "beacon" when put it on the tent.
Anyone familiar with those Zinc-Carbon flashlights would know they can flash short and it is useless as beacon.

d)
After first flashligh is exchausted, there was a second flashlight found at halfway to the Cedar tree.
Again, I don't think, it was simply "lost"
It probably ran out of power during their descent, and they had no choice but to leave it behind.

e)
From the moment they dropped the second flashlight, they have been moving in complete darkness—into the unknown.
This must have been terrifying and devastating for their morale.
Perhaps they believed they were heading toward the supply depot (possibly by mistake).
But how could they hope to find it in total darkness?

Later, when they making a fire or building a shelter, they was operating entirely blind, relying on instinct and touch.

f)
If Krivonischenko and Doroshenko froze to death in the dark under the Cedar tree,
Kolevatov and others, they was building schelter 100 meters away.
How did Kolevatov found their bodies lying dead under the Cedar?
We know he found them (they was lying as dead), because he took over their clothing.
Was it easy to find anything in those conditions?

g)
When reserchers found Dyatlov flashligh at tent and they noticed it was still operable (flashing),
explanation could be simple: Zinc-Carbon batteries can regenerate itself.
I remember - my exchausted Zinc-Carbon  batteries, used a week later, it was able to flash for 1, 2 minutes, again, before exchausing, again.

[GlennM]

Also, since they carried matches, there was no need to save battery power to start a fire.

[Osi]

It is important to have a durable light source in the tent during the time spent in the tent, especially during dinner and subsequent activities. Even today, creating a bright environment with battery-powered flashlights is not economical and may be insufficient in terms of durability. I've been lazy about tent inventory and I'm writing about this topic without researching it. Was there an oil lamp in the tent?
Flashlights were not needed. The movement was made during the day and the light of the fire burning in front of the tent must have illuminated the entrance of the tent while camping at night. Thus, they could easily handle their work in the tent. That's why the flashlights were forgotten at the bottom of the backpack. Since there was no fire on the Kholat slope, lanterns were used to provide light for dinner and we could find them around the tent and a little further away.

[trockey]

Was there an oil lamp in the tent?

Probably, there was not.
It is interesting but two flashlight was found near tent, only. Maybe another was left at cache/deposit.
2x flashlights - It is not much - they plan to travel 20 days.
And their single flashligh was able to operate for 12 hours.
But poor light (10-15 lumens)

I checked this way:
Watt bulb power: 3 Watt
3x Zinc-Carbo baterries R20 (D) 8Ah = 3 x 1.5 Volt x 8 Ah = 12 hours  - so long??????

[GlennM]

The flashlight, better for searching through a rucksack in the dark. Better for getting to and from a latrine. Better for signalling by line of sight in good conditions. Not so good for sustained illumination. Did the unknown compelling force necessitate the use of a flashlight?  I think not.

[Senin]

In a field of white snow even a weak light is enough to see shapes and surroundings

[Arjan]

Ad a)
With full moon and a clear sky, one can do nearly everything outside during night time, except ..... reading.
Some 5 years ago, I have checked the vision of the moon at the beginning of February 1959, if my memory serves me well, I had been half moon.
If this memory is correct, then group members had been able to walk to the cedar and ravine area without any problem in case it had been a clear night.

Remark: a white flash light blinds the night vision of human eyes for many minutes. To have a good night vision it is necessary to abstain from using a flash light, or use a red filter before the flash light.

Ad b)
Very probably the batteries of the flash lights had lasted only max. few hours during a cold clear night outside.

Ad c)
In case group members had stayed behind in the tent, while other group members had descended, the flash light on top of the tent - found switched off - may had the purpose to guide group members from the cedar/ravine area back to the tent, when these group members had arrived at the switched on flash light halfway. Half way these group members returning had very probably been within shouting distance from the tent.

The flashlight on the tent may as well have been used as communication channel to the cedar area: via morse code at fixed time of via short burst of light at fixed time.


Ad d)
In case the flash light - found switched on - in the middle between the tent and cedar/ravine had been used as beacon to return to the tent, then very probably it had been placed at that place by group members descending in order to return within an hour or so.
If so, I makes fully sense seen from these descending group members. This beacon would last a few hours max.

Ad e)
During a clear night with half moon, the group members near the cedar ravine area had been able to perform all kind of survival activities like carefully walking to the ravine, or gathering firewood, climbing the tree to look in the direction of the tent and if applicable: returning to the tent.

There may had been one reason why healthy group members had not returned to the tent:
Luydmila, Semyon and Thibo had been fatally/seriously injured at the end of the afternoon: the healthy group members would never had left the wounded behind at the cedar/ravine area.

Ad f)
See my post "Hypothermia - a timeline'

Group members staying in the tent had had a cold night, but they had survived easily covered by many blankets in re-erected tent on one broken ski-pole.
These group members are candidates to have placed the fatally undercooled group members in the cedar/ravine area in the postures as found by the two search parties.

Ad g)
Maybe, but the explanation that this flash light had the purpose of communication system to the flash light halfway and to the cedar area makes equal sense.