transpose a range to a single column

UDF, if you like?
1) hit Alt + F11 to open vb Editor
2) go to [Insert] -> [Module] Then paste the code onto the blank space in the right pane
3) click x to close the window to get back to excel

select the number of cells (15 in your case) vertically and enter

=TransP(B1:D5)

and confirm with Ctrl + Shift + Enter (array forumla)

Function TransP(rng As Range)
Dim r As Range, a(), i As Long
Redim a(1 To rng.Count, 1 To 1)
For Each r In rng
     i = i + 1
     a(i, 1) = r.Value
     If r.HasFormula Then a(i, 1) = r.Formula
Next
TransP = a
End Function