I think this might work as a 3 way stalemate line, but would never occur in a game:
England:
Centers: Lvp, Lon, Por (3)
Orders: Mao H, Nao s Mao, Por s Mao (3)
Turkey:
Centers: Nap, Rom, Ven, Tri, Vie, Bud, Ser, Gre, Bul, Rum, Sev, Ank, Smy, Con (14)
Venice must be a fleet and Tuscany must be an army.
Orders: U Sev H, F Bla S Sev, U Rum H, U Bul s Rum, A Bud s Vie, A Vie h, A Tyr s Vie, F Ven H, A Tus H, U Rom S Tus, F Nap S Tyrr, F Ion S Tyrr, F Tyrr h (13)
Italy:
Centers: all others. (17)
Italy cannot have any fleets in the north, or an army in England, even though he must have Edinburgh. Piedmont must be a fleet.
Orders: A Mos s Ukr, A Ukr s Gal, A War s Gal, A Gal h, A Sil s Boh, A Mun s boh, A Boh h, U Mar s Pie, F Pie h, A Gas s Spa, F Gol s Spa, F Spa h, A bre h, F Wes s Tun, F Naf, s Tun, U Tun h (16)
Even though England could have taken any number of exposed supply centers before this arrangement was set up, he cannot try to take them now that the line is set up. If he did, Italy would be able to enter the north with his fleets, which would inevitably mean a victory for Italy.