Hit a log lately?

[Mac2]

This chat spawned from the single vs twin engine debate. I introduced the variable of damage when considering single vs twin. Boating locations will determine the threat level, but hitting something is hitting something. Can you comment on your experiences of grounding/hitting something and weather you had damage (cost of repairs), or no damage. Please reference twin vs single. As an example, Ive owned two boats for over 20 years. Both have protected running gear-single with running gear protected by keel, and twin with running gear protected by skegs. Ive hit logs with both. No damage. In the PNW I can’t imagine any boater not hitting some sort of wood debris. I also probably touched bottom (based on the stirred up mud) with my single, but powered out of the situation with my keel dragging the bottom. Did your trip get cut short (damage) due to having a single, or could you continue because you had twins? This chat is for the new/dreamer boaters shopping for a boat. Veteran boaters here already know what they want and why they want it. I just want to add perspective to the conversation.

 

[rslifkin]

We have twins with exposed running gear. We do have a keel, but it's a few inches shallower than the props.

We've hit debris a handful of times. Only one that involved damage was in a shallow harbor, we found some bit of debris sticking up from the bottom. Tapped it with a prop in reverse and very slightly tweaked the trailing edge of 1 blade (took me a few minutes to even find the damage when I looked at the prop out of the water). That one was close to the end of the season, so we just finished out the season with a restriction to slow cruise (no vibration or impact on speed at slow cruise, but the damage caused that prop to cavitate severely with the resulting speed and vibration penalty if we tried to run the boat on plane).

All of the floating debris hits we've had have been without damage, although they've all happened at slow cruise. On plane it would be a different story I'm sure as we'd be more likely to go right over the top of the debris and feed it right into one or both props. But we rarely run on plane and never in water with significant debris concerns.

The hits we've had have gone a few ways. Some have just been pushed aside, some have thumped off the hull and been knocked to the side. A few have been floating far enough below the surface to hit the keel and get knocked down under the props and rudders. A couple of times I've heard a thump or 2 against the keel and looked behind us in time to see a piece of wood float up to the surface in our wake, then sink back out of sight. One of those incidents was a hard enough hit to feel like the entire boat had been dropped onto concrete. Never saw what we hit, but also didn't have any damage. Couldn't even definitively say we had a mark on the paint from that one. One other time I got the thump followed by the metallic clang of a prop or rudder hit. I'm thinking it was a rudder or shaft hit, as it was just a single clang with no resulting damage. We were in a harbor when that one happened, so only doing about 5 kts.

In general, I'd prefer if we had some protection in front of the props, but it hasn't been a big issue for us. The biggest risk for our layout is hitting something sticking up from the bottom in shallow water (where it may find a prop first) or running aground somewhere with very little slope to the bottom (props will hit first as they sit about 5" below the keel). Given enough slope to the bottom we'd hit keel first with the props still off the bottom. We draw 3'6" (fully loaded in fresh water), so I generally treat it as "I won't take this boat anywhere I wouldn't take a 5' draft sailboat"

 

[Comodave]

Our last boat was a 41’ President. We bought it in Virginia and ran it home for 45 days. Coming up the Hudson River we hit at least a dozen concealed logs or trees. It was early spring and there was a ton of garbage in the river. A lot of the strikes were hard enough to shake the whole boat all the way up to the flybridge. I was sure that we would have to rebuild, at least, the props. But when we got home and hauled the boat there was absolutely no damage to the props. The keel in that boat extended about 5” or so below the props and thus protected them. Our current boat would have sustained damage for sure. But the old tales of twin engine boats having prop damage didn’t hold true with the President.

 

[Mac2]

We have twins with exposed running gear. We do have a keel, but it's a few inches shallower than the props.

We've hit debris a handful of times. Only one that involved damage was in a shallow harbor, we found some bit of debris sticking up from the bottom. Tapped it with a prop in reverse and very slightly tweaked the trailing edge of 1 blade (took me a few minutes to even find the damage when I looked at the prop out of the water). That one was close to the end of the season, so we just finished out the season with a restriction to slow cruise (no vibration or impact on speed at slow cruise, but the damage caused that prop to cavitate severely with the resulting speed and vibration penalty if we tried to run the boat on plane).

All of the floating debris hits we've had have been without damage, although they've all happened at slow cruise. On plane it would be a different story I'm sure as we'd be more likely to go right over the top of the debris and feed it right into one or both props. But we rarely run on plane and never in water with significant debris concerns.

The hits we've had have gone a few ways. Some have just been pushed aside, some have thumped off the hull and been knocked to the side. A few have been floating far enough below the surface to hit the keel and get knocked down under the props and rudders. A couple of times I've heard a thump or 2 against the keel and looked behind us in time to see a piece of wood float up to the surface in our wake, then sink back out of sight. One of those incidents was a hard enough hit to feel like the entire boat had been dropped onto concrete. Never saw what we hit, but also didn't have any damage. Couldn't even definitively say we had a mark on the paint from that one. One other time I got the thump followed by the metallic clang of a prop or rudder hit. I'm thinking it was a rudder or shaft hit, as it was just a single clang with no resulting damage. We were in a harbor when that one happened, so only doing about 5 kts.

In general, I'd prefer if we had some protection in front of the props, but it hasn't been a big issue for us. The biggest risk for our layout is hitting something sticking up from the bottom in shallow water (where it may find a prop first) or running aground somewhere with very little slope to the bottom (props will hit first as they sit about 5" below the keel). Given enough slope to the bottom we'd hit keel first with the props still off the bottom. We draw 3'6" (fully loaded in fresh water), so I generally treat it as "I won't take this boat anywhere I wouldn't take a 5' draft sailboat"

Your on the opposite coast, yet we have had the same experiences. I think the big difference, as you stated, is the speed at which you make contact. When doing a bottom job last summer, I noticed a football sized dent (1/2 inch depth in 1/4 steel) between the centerline and chine. No bottom paint was missing, so from a PO. This was halfway down the hull at a four foot depth location. No other damage, so that was the initial contact point. More than likely a dead head (log straight up and down below the surface).

 

[rslifkin]

Your on the opposite coast, yet we have had the same experiences. I think the big difference, as you stated, is the speed at which you make contact. When doing a bottom job last summer, I noticed a football sized dent (1/2 inch depth in 1/4 steel) between the centerline and chine. No bottom paint was missing, so from a PO. This was halfway down the hull at a four foot depth location. No other damage, so that was the initial contact point. More than likely a dead head (log straight up and down below the surface).

Speed is definitely a big factor. Anything running below hull speed has a reasonable shot at pushing or kicking debris out of the way on impact. Exactly how that happens will depend on where it hits first and the hull shape. A boat on plane is running on the water more than in it, so it's more likely to go over any debris without knocking the debris away from the props unless there's something directly in front of the props to redirect it. The impact force is also higher on the faster moving boat, so more chance of doing damage to whatever the debris hits first.

 

[SteveK]

going upriver, headed to the haul out location I hit something below water line at the stern, in the the shaft/prop area. Inspected in sling and found no evidence of damage, that was two years ago.
Saw 3 vertical deadheads this year, one was flagged, those can be brutal if nailed. Surface logs and debris can be avoided but sure will do damage if crossed over at speed.

 

[tiltrider1]

I don’t think there is much Debate between single vs dual. If you need range, you need a single. If you are poor you can only afford a single. The rest of us are better off with duals.

When I was poor I had a single, I got towed home once. Now I have duals, I have never been towed home.

 

[Mac2]

I don’t think there is much Debate between single vs dual. If you need range, you need a single. If you are poor you can only afford a single. The rest of us are better off with duals.

When I was poor I had a single, I got towed home once. Now I have duals, I have never been towed home.

I don’t want a general debate about pros and cons of single vs twin. This is more about the difference in cost due to damage, or the cost (emotional) of having to cancel a trip due to damage-not sure how you measure that. So far we are getting comments about multiple strikes in a variety of cruising grounds.

 

[tiltrider1]

I don’t want a general debate about pros and cons of single vs twin. This is more about the difference in cost due to damage, or the cost (emotional) of having to cancel a trip due to damage-not sure how you measure that. So far we are getting comments about multiple strikes in a variety of cruising grounds.

All I am saying is that I never had my trip end with duals but I have with a single.

This year was particularly bad north of Vancouver Island. Early in the year there was an unusual amount of rain fall that resulted in very large slides depositing a lot of debris. Later in the year there was a massive ice dam that scoured Tracy’s Arm depositing all mater of tree product in all of SE Alaska.

I haven’t had a log strike in years and yet, I had 3 this year alone(no damage). Still, the only damage I saw was to a boat traveling 30 knots that got a log caught in its running gear. Definitely ended their vacation but they made it 80 miles to Wrangell on their own. While one might make the argument that it wouldn’t have happened if they were running a single, I would make the argument that this wouldn’t have happened at 10kts.

 

[ranger58sb]

Haven't hit solid stuff... yet... (not counting dirt, of course)...

But we did catch a crab pot float with this boat, starboard shaft, instant engine shut-down. Didn't get towed for that; we were able to back off the line and then it was just like nothing happened.

OTOH, we've had to replace the output flange seal afterwards, I think possibly related to the trap incident... although the gear guy said it might instead have just been due to wear and tear over time. (But we first noticed it only after the jerk stop.)

When I was poor I had a single, I got towed home once. Now I have duals, I have never been towed home.

Heh... we had a single, never towed. Have duals now, got towed... due to an electronic gear control issue, which affected both gears so we couldn't even limp home by ourselves on one engine.

Tre embarrassing, a boat named Ranger being towed by a TowBoatUS boat named... Ranger. Gak!

-Chris

 

[slowgoesit]

I've owned four singles 34' to 50', all 8 kts or less. First one, hit log in PNW, dinged prop and shaft, but was able to make it home under my own power.
Our current boat, we've hit stuff at cruise, never saw it, thumped on hull, heard throughout boat, no noticeable damage.

 

[Mac2]

First one, hit log in PNW, dinged prop and shaft

Seems like a long shot to get a shaft ding with the shaft coming out of the keel and such little shaft exposure. You think the log got wedged between the prop and keel? Do you recall the cost of repairs and haul out?

 

[Ken E.]

.....In the PNW I can’t imagine any boater not hitting some sort of wood debris....

Amen to that, the question is when your time will come and how big the log will be. Going slow helps a lot, as does someone vigilant at the helm, watching for debris. It's very easy for the person driving to get distracted, especially by conversation or if you allow computer games while driving. We don't. I have twins, with a keel but the props are exposed. A single with a big keel has a chance to avoid serious damage in a log strike. Again, the best defense is to go slow and pay attention while driving.

 

[Mac2]

Going slow helps a lot, as does someone vigilant at the helm, watching for debris. It's very easy for the person driving to get distracted,

I love my auto pilot and I hate my auto pilot. It makes it less tiring on long slow 8 knot cruises, but way easier to be distracted. Last time I ran over an easily seen log (as noted in my wake) I realized it probably wasn’t the best idea to have moved a small tv to my dash. Apparently that ticket for texting and driving has some validity

 

[slowgoesit]

Seems like a long shot to get a shaft ding with the shaft coming out of the keel and such little shaft exposure. You think the log got wedged between the prop and keel? Do you recall the cost of repairs and haul out?

I have no idea the dynamics of the contact, we DID hear the strike, and rumbling sound, which I interpreted as the log rolling between bottom of keel and turn of the bilge. Prop had damage, but repairable. Shaft was 1.5" bronze shaft, 14.5' long, which was damaged and replaced with stainless steel shaft fabbed in Renton, WA, circa 1981 at the cost of about $700.00. Rudder was also damaged beyond repair. Shop in Tacoma straightened the bronze rudder, bondo'ed it to perfection, then made sand mold of the rudder, and cast a new rudder using upper and lower 1.5" bronze rod, and machined the top of the rudder stock to a square to fit the emergency tiller. Total cost for rudder was under $400 . . . back in 1981. Don't remember the cost of straightening/tuning up the prop, which IIRC was around 14.5" diameter.
This was on a 1959, 34' Ed Monk SR designed boat. Strike was under the Tacoma Narrows Bridge, North Bound at night.

 

[Mac2]

I have no idea the dynamics of the contact, we DID hear the strike, and rumbling sound, which I interpreted as the log rolling between bottom of keel and turn of the bilge. Prop had damage, but repairable. Shaft was 1.5" bronze shaft, 14.5' long, which was damaged and replaced with stainless steel shaft fabbed in Renton, WA, circa 1981 at the cost of about $700.00. Rudder was also damaged beyond repair. Shop in Tacoma straightened the bronze rudder, bondo'ed it to perfection, then made sand mold of the rudder, and cast a new rudder using upper and lower 1.5" bronze rod, and machined the top of the rudder stock to a square to fit the emergency tiller. Total cost for rudder was under $400 . . . back in 1981. Don't remember the cost of straightening/tuning up the prop, which IIRC was around 14.5" diameter.
This was on a 1959, 34' Ed Monk SR designed boat. Strike was under the Tacoma Narrows Bridge, North Bound at night.

Thanks for that detailed report. Did that boat have a full keel (extending under the prop?

 

[Portage_Bay]

Unprotected twins.

Stuck it in the mud trying to get past a boat grounded on the opposite of the channel. Had to wiggle off. No damage.

Hit something that stalled the port engine and the boat stopped like I'd backed down. Looking over the side and under the transom I couldn't see anything so restarted and tried reverse thinking it might be a crab pot line, abandoned line or net. Stalled again. We headed to the nearest dock at 1.5 kts. No damage. $250 for the diver to clear it. We didn't know what it was till the diver pulled it out. A large foam pad about 6" thick the size of a twin bed covered in heavy black fabric. A big foam parachute will really slow you down. It must have been submerged to not see something that big.

Many minor strikes. Wood. Thumped down the side of the boat without damage. Numerous crab pot scares when the tide is running hard and the float is nearly submerged.

 

[O C Diver]

In 6,000 hours, I've only dinged a prop once and was able to get to the boat yard. In 8,000 hours with my charter boat I never dinged the prop.

IMO, if traveling in displacement, it's doubtful a log strike will require a tow home. Traveling at planing speed is a different story.

For me, twins are a requirement for engine failure in remote locations. If I were cruising Alaska, the Caribbean, or some other form of passage making, where engine failure would put me at great risk more than 5% of the time, I would have had twins.

What has always amazed me, where twins are required for remoteness, I have yet to meet someone who maintains them as well as the average single engine owner.

Ted

 

[Bacchus]

I don’t think there is much Debate between single vs dual. If you need range, you need a single. If you are poor you can only afford a single. The rest of us are better off with duals.

When I was poor I had a single, I got towed home once. Now I have duals, I have never been towed home.

Many will disagree on fuel consumption of single vs twins. It certainly depends on size of each and design for intended use.
"Better off" is largely in the eye of the beholder. Not trying to disparage anyone's choice of twins for their situation but IMO it really depends on more things than being able to afford 2 engines. & gear.

Have you had to get home on one of you twins?

 

[Fletcher500]

I only have limited chartering experience in the PNW and never hit a log, but heard a few stories from locals up there.

I was heading down coast off Pt Dume four years ago and had a bow impact that shuddered throughout the boat. Felt like a truck hit me. My first thought was a shipping container, it wasn’t. Then a second impact, port side aft. I immediately cut the engine and looked aft and saw a large dorsal fin flailing in the water which I figured was a great white. On closer examination it was a massive sunfish with a 3-4 ft dorsal and was probably close to 1K lbs. I hope it survived, not sure. I am fairly sure if I had fins, a rotor, or other external stabilization appendage, the second impact would have severely damaged it or ripped it off. It didn't involve the running gear at all.

As far as rudder protection, I have had a few close calls, but its not as important down here as it is up there.

 

[Mac2]

What has always amazed me, where twins are required for remoteness, I have yet to meet someone who maintains them as well as the average single engine owner.

How would you ever measure that? If you’re lazy, you’re lazy. Doesn’t matter how many engines you have. The only difference for me to compare is the amount of alarms I added to my single engine (water flow, oil pressure, exhaust temp, engine temperature).

 

[SteveK]

Have you had to get home on one of you twins?

Yes

 

[tiltrider1]

Many will disagree on fuel consumption of single vs twins. It certainly depends on size of each and design for intended use.
"Better off" is largely in the eye of the beholder. Not trying to disparage anyone's choice of twins for their situation but IMO it really depends on more things than being able to afford 2 engines. & gear.

Have you had to get home on one of you twins?

Yes, on two occasions. One was a bearing failure in a raw water pump. Pump was only 3 years old so it was very unexpected. Happened a day away from Sitka and two days away from Petersburg. Would have been very difficult to get help. The first time was a bearing failure of the engine coolant pump. This was 4 hours after I acquired the boat, some were between LA and Santa Barbara. I knew I was taking Some risk with an unknown boat but I also knew that I had two engines. Limped Her inTO Santa Barbara where a new pump was delivered.

 

[C lectric]

Our long gone (40 yrs ago) 28ft Chris Craft suffered a planing hit. One rudder is still at the ocean bottom, the props were repairable, one shaft bent although repairable also.
Twas caused at least partly because to use my VHF I HAD to completely take my eyes off the water ahead. The VHF was down by my side which took my eyes completely off the course ahead and thus the water and any debris.
It was a log and although I tried to dodge it after killing the throttle it was not enough.
We had leaks but luckily the water ingress could be handled by the bilge pump.
It took 4-5 hrs to get back to where we could get a lift when it only took about 45 mins to get where we were.

THe Coast Guard came out with a gas powered pump and dropped it off. Two of them came aboard and assessed the damage as well as possible. We did not need panic repairs or a tow BUT that decision came much later. We returned the pump several hours later after the boat was lifted onto shore.

Ss soon as I got the repaired boat back the VHF was MOVED to over head and forward easily within reach ahead of me and higher so all I needed was a glance at it. A glance at the water ahead served us well over the next number of years and we saw other logs in disguise over the next few years.

We were very lucky. THe seas were calm, we were travelling with two other boats one of which escorted us back to the nearest marina. We told the other boat to carry on as we did not need twin escorts and we had determined we were not sinking as we had bobbed about for between one and two hours before we could get moving again.

So take a good look at your VHF as it could be critical to ANY help available and if visibility is forward easily at a glance it may save your bacon/boat and you.

 

[rslifkin]

What has always amazed me, where twins are required for remoteness, I have yet to meet someone who maintains them as well as the average single engine owner.

I'm of the opinion that far too many boat owners don't maintain their engines well enough regardless of single or twins. And far too many aren't picky enough about making sure they behave perfectly and are all too happy to live with quirky behavior.

 

[Bacchus]

@StevK and tiltrider1
That reinforces the benefit of twins in your situations & cruising. I stand by my comment that "it depends" on more that if you can afford twins.

 

[O C Diver]

How would you ever measure that? If you’re lazy, you’re lazy. Doesn’t matter how many engines you have. The only difference for me to compare is the amount of alarms I added to my single engine (water flow, oil pressure, exhaust temp, engine temperature).

Start with following the manufacturer's book on maintenance intervals.

Replacing oil and filter
Valve adjustments
Replacing coolant
Replacing thermostat(s)
Replacing radiator cap
Replacing coolant pump before failure
Replacing anodes
Replacing raw water impellers
Replacing raw water pump before failure
Replacing idler pulleys before failure
Replacing serpentine belt before failure

Having spare starter, alternator, serpentine belt, idler pulleys, raw water pump, impellers, freshwater pump, thermostats, radiator cap, anodes, filters, fuel pump, oil, antifreeze, gaskets, coolant hoses, and that's just off the top of my head.

Ted

 

[Jeff F]

I've hit numerous big logs and various other debris on the rivers in my single engine boats. AFAIK that's never caused damage to the prop. If I'm alert I'll get into neutral fast after hitting. Have had big logs bump the prop and rudder on my current boat, but the keel is a few inches deeper and gives them reasonable protection.

I've significantly damaged my prop twice, both times striking hard bottom in places I shouldn't have been. Both times I ran under my own power to a local boat yard, did a short haul and swapped to my spare prop, then had the damaged one repaired. Inconvenient, but not a big deal.

Ive picked up crab/lobster/net lines four times that I'm aware of. None have been disabling events.

I agree with others that it's speed dependent. Part of the appeal for me of my normal 6-7 knot boat speed is that I'm pretty confident that my single engine military spec boat will survive a direct hit on just about anything

I can only dream of being rich enough to own a twin engine boat, but I'm OK with that.

 

[tiltrider1]

Having spare starter, alternator, serpentine belt, idler pulleys, raw water pump, impellers, freshwater pump, thermostats, radiator cap, anodes, filters, fuel pump, oil, antifreeze, gaskets, coolant hoses, and that's just off the top of my head.

Ted

I really agree with this statement if you are running a single. Preventative maintenance alone is not enough, you need all these spares because you can't know when some manufacturing defect is going to show up. Essentially you have all this with twins. Despite having twins I now carry a spare starter and a spare raw water pump.

 

[O C Diver]

Essentially you have all this with twins. Despite having twins I now carry a spare starter and a spare raw water pump.

True, twice as many failure points on neglected engines. Aviation has learned that twin engine aircraft can fly with a single engine failure, provided that strict attention to following maintenance protocols is followed.

Ted