Path: csiph.com!fu-berlin.de!uni-berlin.de!individual.net!not-for-mail From: "Carlos E. R." Newsgroups: comp.os.linux.advocacy,comp.os.linux.misc Subject: Re: OT - TV Date: Fri, 9 Oct 2026 22:32:09 +0200 Lines: 37 Message-ID: References: <118cshs$2v7m0$1@dont-email.me> <11991m3$mv9t$1@dont-email.me> <119as35$18kn0$1@dont-email.me> <119bbo8$1e3hu$1@dont-email.me> <119is9d$68cr$1@dont-email.me> <119j2qg$8pgq$1@dont-email.me> <119m338.o7c.1@ID-201911.user.individual.net> <119qnr6$2urls$1@dont-email.me> <119qr92$2vglb$2@dont-email.me> <119r8k4$3515t$1@dont-email.me> <119tba1$3quvc$1@dont-email.me> <11a38uf$24fks$1@dont-email.me> <11a4u79$2lnse$1@dont-email.me> <11a55g7$2nipf$4@dont-email.me> <11a5at8$2nipf$18@dont-email.me> <11a80sh$3pnm3$4@dont-email.me> <11a90dj$7ae1$1@dont-email.me> Mime-Version: 1.0 Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 8bit X-Trace: individual.net vbDexFJFvZ42/ptx6MkjFgzpfqDprKvn+qBINlixUkH3cDEUNb Cancel-Lock: sha1:es0JWU/DZ239ikIvwu75a5S8xPw= sha256:t2V8J0IqI3DOYdaQXRvlGPiFxurAaKiIUhg1cRQlU2Q= User-Agent: Mozilla Thunderbird Content-Language: en-GB In-Reply-To: Xref: csiph.com comp.os.linux.advocacy:723540 comp.os.linux.misc:93255 On 2026-10-09 04:28, rbowman wrote: > On Thu, 8 Oct 2026 22:02:41 +0100, J. P. Gilliver wrote: > >> If your journey involves about the same amount of uphill and downhill, >> and you're _not_ using the brakes, where is the downhill energy going? >> Either engine braking (which is another form of "using the brakes", but >> even worse in that it might actually use fuel), or you're accelerating >> on the downhill parts and using the speed thus gained to help you on the >> uphill - >> makes you a bit dangerous in the valleys. > > The trucks I drove mostly had Jake brakes but a couple had simple exhaust > brakes. You were off the throttle so little or no fuel was being injected > but you were not reclaiming any energy. > > https://en.wikipedia.org/wiki/Jacobs_Vehicle_Systems > > Many of the eastern trucks weren't equipped and like Clessie Cummins came > off Cajon rather rapidly with smoking brakes. That's what the runaway > ramps are for. > > I did haul a load to West Virginia. The exhaust retarder wasn't working > and the shop was waiting on parts. The shop foreman said 'No problems. > You're going east and we'll fix it when you get back.' He apparently had > never been to WV. They might not be 7 mile grades but they make up for the > lack of length with the grade. Over here big trucks (I don't know about tractor+trailers, harder to see) have some sort of electric brake. Seems like a big generator installed on the longitudinal axle. Maybe they short circuit it, or put some resistors across the terminals. Or maybe they apply battery electricity to electromagnets near a moving metal disc(s). -- Cheers, Carlos E.R. ES🇪🇸, EU🇪🇺.