AirChime K5LA

In 1975, Amtrak's Deane Ellsworth presented a variation from the usual K5H to modify bells #3 and #4 to change the key from D# minor 6th( Dm6 ) to B major 6th ( B6 ). Thus, the Airchime K5LA was born. Although originally they were for Amtrak use, the first ever K5LA's were installed to GP40-2 locomotives on a purchase by Chessie System. Presently, the train horn is a staple on Amtrak and several commuter railroads in thus. Also using the bells are Norfolk Southern and CSXon their freight carriers. K5LAR24 bells were installed by Union Pacific on their new SD70M locomotives in 2001. Some other shortlines are using the horns as well.

Common arrangements of the horn had several variations, freight railroads prefer more bells to be reversed. Reversing the #2 and #4a bells give out a designation of K5LAR24. If you reverse 2 and #4a bells it designates it to a K5LAR23. Usually K5LA horns have #5, #3a, #1, #2 and #4a bells. The "A" in the designation represents "American" tuning, and the "L" represents that it has a low-profile manifold. This was intended for Amtrak to follow clearance requirements.

Another rare arrangement is the K5HA, "H" meaning it has an H manifold. But usually, K5LA had all five bells in a low arc arrangement. Amtrak also received some K5LA's with horn bells spread over in two manifolds, suggesting 2 bells on one manifold and 3 on the other base. This arrangement was primarily used by Amtrak as an alternative to the Leslie SL-4T horns that were later on installed on SDP40F locomotives. Amtrak F40PH locomotives had cones that can be installed to keep the bells clean.

The external design of the K5LA's, were very common compared to other K-series models. But Internal design was as loud as a large billboard. Residents along the tracks regularly complained about it, especially during operations at night. Amtrak didn't give out the cold shoulder on this, but instead took steps to minimize or eliminate the problem. Amtrak installed choke fittings to quiet the horns or transfer the horns in a position that sound will be directed onto the tracks and not the corridors of the tracks.