[In the following the B path is a mirror image of the A path.
If E is a common rest frame, then the A-clock will run slower than the E-clock by a factor of .92. If the A=clock shows 100 then the E-clock shows 109.
(you have the relation of frames reversed)
The speed of B relative to A is .80/1.16 = .69c giving a clock rate of .52.*
They simply add in Newtonian physics but not in SR.
Why would you mix Newtonian and SR methods?]
*[In the graphic while A and B approach E, A sends a signal (123) to B for a distance measurement. Event 3 is horizontally transferred to the vertical At time scale. The distance is d. The 2nd distance is 0 when A and B meet. The speed of B relative to A is line (1-5)/ line (1-4) = .69c. This geometric method is in agreement with the SR composition of velocities.]
[Your example shows you don't understand SR, and want to remain in the Newtonian/Galilean world of absolute concepts. Good luck with that.]
I know how you can get this result. I see what you are doing. But its rubbish.
Before you can use Minkowski diagrams, you have to prove that they mean something related to physics. They are just foolish abortions of geometry, nothing more. You cant explain WHY anyone in their right mind should change a velocity vector into a "world line" and then you have no rational excuse to claim that this new Time axis should be mirrored about the 45-degree velocity vector of light.
And since the Minkowski diagram is based on SR, it can't be used to prove SR. It may be used once one accepts the hypothesis of SR as a way to explain the twisted logic.
So I repeat, its no point in using math of geometry to derive your results, before you can explain how he concept can be anything but irrational posturings.
What is the reason for having two calculations for the velocity of the one spaceship relative to the other one?
Rational logical thought says that once you know the speed of A and B then there can be no further knowledge to be had about this scenario.
What you are saying is a direct contradiction, one object has two velocities. It CANT.
Explain the logic behind your claim, then if its sound, we can look at how you come up with the exact numbers. Using Minkowski diagram if you want, but only after you explain why that horrible crap could be possible.
Or use your Lorentz contraction equations, but once again you need to demonstrate that the equation is based on sound logic. It isn't.
So first up, before you say anything else, explain how it's possible for one object to possess two different speeds.
We only have 3 objects here. 2 ships, and one tree (E) we know the locations of all three objects, and the speeds of the two ships relative to the tree, therefore by deductive reasoning, we know the speed of the two ships relative to each other.
So go ahead, explain why this it wrong, and the ships possess two speeds.
I'm looking at these three objects from a reference place that places the tree as a non-moving object, as are the occupants of the shipos, they also use the tree as their reference for velocity.
Now please proceed with your explanation. You cant use any math or weird diagrams based on your explanation until we can see that your explanation is rational and logical. Graphs and math don't EXPLAIN how it works, they just allow you to come up with working examples based on your hypothesis, so they are NOT necessary to use in an explanation of the Hypothesis.
Einstein in his 1905 paper attempted to hypothesize that a single pulse of light would do two different things if seen from two different vantage points. He then used math to provide working examples.
But trouble is, his hypothesis about the two things light would do at the same time, was totally flawed. Its an irrational and impossible claim.
So to be clear, I need you to only explain one thing.
How it's possible to have two have the ships going at two different speeds when we are observing the whole scenario as a single process.
We are not hopping between reference frames, we are watching all three objects and it's IMPOSSIBLE that a ship can have two different velocities. If something is IMPOSSIBLE, its IMPOSSIBLE in another frame of reference too.