You both are thinking of the smell of frying chips. Clearly either of you have ever had to put out a deep fryer fire. Had you had done so, you would known what that would smell like. Once cooking oil reaches its smoking point -- the temperature at which it begins to chemically break down and smoke continuously. At this point, the fat molecules break down into glycerol and free-fatty acids, and the glycerol breaks down further to produce toxic fumes and free radicals. The smell of burning cooking oil reeks and the odor can persist for days. As for the smell bothered anybody, you may like the smell of brunt cooking oil most people don't. In the case of Swanage, Station Road is the retail centre of the town and the road is lined with shops and cafes. The oder drives away custom as people go elsewhere to get away from the smell. Good thing that the Web was not around then.
Alright, chill out, we were only joking.
But that's besides the point - as I mentioned earlier in the thread, the reclaimed biofuel the Grand Canyon Railway were burning was practically odourless - the refinement process has come a long way in the past 35 years!
Perhaps you could use it when your large engine is pottering around at 25mph on a preserved line, and save the real stuff for main line outings?
Exactly this - it may not be viable for mainline operations for the time being, but there's no reason a locomotive on a preserved line that at most maybe does 100 miles a day with 5-7 coach trains couldn't feasibly use it. The Grand Canyon Railway is 60 miles long (so a 120-mile round trip), uphill for most of the outward journey, and their locos (2-8-2s) have managed just fine for the past 10 years.
Without meaning to be too blasé about it, Steam Railway's "research" seems to be blinkered by a misguided assumption that locomotives on heritage lines need to perfectly match their as-built mainline performance and range on coal firing.
While I'm sounding like a skipping record bringing up the Grand Canyon Railway again and again, I can't reiterate enough that there are already mainline steam locomotives out there pulling loaded trains on routes far longer and more challenging than anything we have in this country.
It's very much a viable alternative, it's just up to a railway to take the plunge and invest in the process of conversion and refinement. That "can-do" spirit that the industry thrives on is going to have to drive any introduction of alternative fuelling,