Old Ship Diagram Special Relativity - Time Dilation.?

Special relativity - time dilation.? - old ship diagram

Why does the presence of a ship on the entire table?

Imagine that the Earth is now 0 years old.
A-and B-boats leave the earth at this point in the same direction.
I think the vessel B is pre-programmed to operate than 1000 years after leaving Earth.

Chart:
E -----> ----> AB

The speed is measured from the earth at 0.6 C, γ = 1.25
Speed of B is measured from 0.6 to A c, γ = 1.25

by the formula of addition of velocities

s = (0.6 C + 0.6 ° C) / (1 + ((0.6 º C 0.6 * C) (C * C)))

s = 0.88235c, γ = 2125

B ship sails at a speed near the earth 0.88235c with γ = 2.125.

That's what I know: when the boat exploded B would be the Earth 1000 * 2125 = 2125 years.

That's what I do not know how old a boat?
1000 * 1.250 = 1250? or
2125 / 1.250 = 1700?

If 1250, then the earth must be 1250 * 1.250 = 1562.5 years?
1700, when then object B has skyrocketed (1,700 / 1,250) - 1,000 years ago?

because the measured Bthat γ = 1.25 A and
As we γ = 1.25 Earth.

my qn is, how old is the object A, and why the equation does not work?