All true, what I was trying to say (badly) was whether a leading F40 could activate the blended braking ( which I don't claim to understand in detail) versus simply controlling the trainset automatic brake via brakeline pressure. The brakes still work, but differently.
Blended braking can be controlled by the 27-pin MU. But as the leading F40 is not able to communicate via the MU and COMM circuits to the rest of the train, then no, it will not activate the blended braking on the training Charger.
Blended braking is activated on the leading loco in this case via the 30CDW brake valve on the desktop and an auxiliary valve located downstream of it who's name currently escapes me.
I do understand that there is no control of the independent brake from the cabcar end. That may not matter when the F40 is pulling, but would possibly matter when it is shoving.
- Paul
There is not, but then again the independent is very, very seldom used in passenger train service. There is no need to bunch up the slack on a small train, and especially on something configured as a fixed consist such as the Chargers and Ventures.
According to groups.io (Lion Liu) the F40 will be dead in tow when at the rear, and was chosen as opposed to P42 due to being lighter.
The weight difference is pretty negligible now that the F40s have been rebuilt with separate HEP engines. But even when new the weight difference was only 8000 pounds, which is not much on a device weighing 260,000 pounds.
But I suspect that the real reason is because the F40s have a separate HEP engine and system as opposed to the combined one of the P42s. This will save on fuel and wear-and-tear, as an F40 being towed does not need to have its main engine running, just the HEP one.
Siemens Chargers are "kaput" in colder climates.
It wasn't just the Chargers - a number of trains over the past week suffered issues with the HEP system giving out in the middle of runs, including a couple powered by P42s and F40s..
Most of the trains operating legacy equipment have been configured with locos at both ends for the past while, so it was easy enough to transfer the HEP to the other loco. But the Siemens sets only have the one loco per set, so this is being done as a back-up.
I've heard some folks (who know more than I do) suggest that the way the Chargers are designed, too much of the inner mechanics and electronics are too exposed to outside temperatures.
This is absolutely not the case. If anything, in some ways the Chargers are better insulated from the cold than the older designs.
Dan