Hmm , you'd have to go back a fair way to find a "mainline" diesel designed for use in NSW that didn't have a dynamic or regen brake incorporated into it . I strongly doubt anyone would buy a road unit that didn't have it . They are not an afterthought which is why the builders here all fit them.
I love it how people always pick and choose what they want to hear and then pick an argument apart based on what they perceive rather than what was actually written. If you recall correctly, I wrote that any mainline locomotive these days should ideally be fitted with dynamic brakes, and they are. However, a gen-set isn't a mainline locomotive, it is nothing more than a glorified shunt or trip engine, and that's why I stated that dynamic brake isn't such a great concern there if it isn't fitted (ideally it should, but this one doesn't for what could be a myriad of reasons). If it was a brand new mainline locomotive, the lack of dynamic brake in this day would be an incredible oversight, but as a trip train engine and potentially as a demonstrator of the type, there might have been reasons to omit it, if indeed it is destined for Australia at all.
There's a reason the American’s don't have gen-set's climbing Soldier Summit or Horseshoe Curve; that's because they're glorified shunters, and any Australian company who tries to do different with a gen-set might find if difficult. Stay within context of what they're designed to do, that's all I'm trying to say.
Myself and others use the dynamic brake shunting at Chullora to hold back heavy rakes particularly when they are long because using the brakes means they stop all the time - which wastes time ……(insert irrelevant rant)… Chokes on a long train are a PITA because they take longer to release than is usefull on less severe grades and the result is you slow down more than you need to and in some cases virtually stop.
Personally, I don’t need a lesson in fixed chokes as the last train I drove was four 48 classes on the front of 40 fixed choke wheat hoppers for 3200 tonne. However, I see your point, and yes everyone has at times used dynamic brake when shunting, especially in situations like you've described. The thing is though, there's a difference between running to Junee on NR's with 1500 meters of containers and heading out to Yennora on a shorter train while doing the Enfield Crawl. A driver drives accordingly, and if a gen-set is ideally suited to trip working, but doesn't have a dynamic brake; then I'd expect the driver to drive accordingly when he is rolling along on the Metrop' Goods Line (momentum anyone?). Afterall, a gen-set isn't a mainline locomotive but a shunter.
No one uses dynamic brakes going up hill - garbage . I had a longish Perth train recently on the up south and use the dyno brake to slow for the TSR at Bundanoon . Came past the 100 in the previous dip doing 98 bunched up against the dynos and went back to rolling and stretching a little above the restricted speed . Had I applied the brakes that train would have come to a stand on the rising grade.
Having driven that exact bit of track, I can understand exactly what you are saying, and for the length of train that sounds decent as being on a high-wheeler you probably would have hit the bottom of the hill at faster speed regardless of the upcoming TSR (while I on the slower runner would have naturally hit the bottom slower and rolled up). In saying that though, you can't tell me anyone would bring the dynamic in to slow for a signal at stop having been travelling uphill for a good while. If someone did, it'd be nothing short of bad train handling and road knowledge regardless of the "chokes". The other thing is, and perhaps the most important thing is that a gen-set won't be hitting 'Shangrila' at 98 on an interstate high-wheeler either. Ideally, it'll be pottering around on a trip train somewhere (if it even gets here), not dropping down Demondrille with 2500 tonnes. Because, afterall it’s only a shunter.
Over time brake shoes cost a lot more than dynamic brake equipment does and allows higher average speeds on grades than brakes alone do . MZs are a silly example because they were never intended for use in places like Australia . They would be a lot slower down the mountains than say a pair of 81s 82 etc and ultimately cost the owners more in train operating costs . The people operating MZs don't do it because they have a choice they do it because they can't afford anything better .
And that's a fact I gave you credit for; however, I used the example of the MZ’s because it shows that it can be done (not that it should be done day in day out though). Granted, we don't live in the steam era anymore, and enginemen don’t bring 1000 tonnes down the mountains on a No4 brake valve, but a locomotive designed to shunt, surely can shunt or trundle backwards and forwards to Botany on the air if need be. Why, because afterall it's a shunter.
All I'm saying is that having a dynamic brake is an essential part of the modern mainline locomotive, while it should also be a part of the shunting engines as well because as you've described, it may need it at times. However, this one doesn't have it (for whatever reason, weight, budget, whatever…), and all I'm saying is that if it does actually arrive here and is used for what it is supposed to do (shunt…), then that's not the end of the world. We've all ridden the independent down the yard, or knocked a quick 50kpa out of the brake pipe during a shunt. It's not ideal in a lot of circumstances, but I think we're all still capable of that aren't we if a demonstrator gen-set happens to turn up?
